Howard and Bernadette began dating in "The Creepy Candy Coating Corollary", were engaged in "The Herb Garden Germination", then they finally married on "The Countdown Reflection". In season 9, they became the first main pairing expecting a child. Their daughter, Halley, was born in the Season 10 episode, "The Birthday Synchronicity". They were expecting another baby as of "The Proposal Proposal". The baby was revealed to be a boy in "The Explosion Implosion". Their son, Neil Michael Wolowitz, was born in "The Neonatal Nomenclature". Howard and Bernadette have been the couple to first experience all the milestones of a relationship throughout the series except the first date.
- "The Creepy Candy Coating Corollary"- Howard was introduced to Bernadette via Penny. Howard asked Leonard to invoke the girlfriend pact where one would set up the other if they got a girlfriend. At first, she and Howard did not get along on their date, since they appeared to have nothing in common. However, when they found out that they both had overbearing mothers they immediately felt a connection.
- "The Vengeance Formulation"- Bernadette asks Howard for a commitment in their relationship. After deliberating, Howard proposes to Bernadette, but she rejects. Their relationship resumed after Howard asked for a second chance when he sang his own rendition of "Bernadette," by The Four Tops.
- "The Plimpton Stimulation"- Howard announces that he and Bernadette broke up a few weeks ago. Howard claims that he did not tell anyone because he was waiting for the "right time."
- "The Hot Troll Deviation"- It is revealed that Howard and Bernadette broke up because she caught Howard having cyber-sex on World of Warcraft with Glacinda the Troll. Howard convinces Penny to help him to get Bernadette to talk to him. After he apologizes, they got back together.
- "The Cohabitation Formulation"- After they had sexual intercourse, Bernadette asked Howard to stay over. He refused, since his mother required his help in the morning. Later that episode, Bernadette decided to tackle Howard's issue, his overbearing mother. She asked him to choose between her or his mother. He ended up choosing her, but, soon after, she realized he was deeply reliant on his mother as well and wanted her to take his mother's place.
- "The Herb Garden Germination"- Rumors about Bernadette’s intention of breaking up with Howard start spreading among their social group. However, Howard, who was left in the dark, is thinking of proposing to Bernadette. When Howard finally popped the question, Bernadette accepted.
- "The Engagement Reaction" - Bernadette meets up with Howard's mother to get to know each other, directly after that Howard breaks the news that he is getting married to Bernadette to his mother, she faints shortly after hearing the news. It turned out his mother only suffered from food poisoning and she approves of Bernadette, but Bernadette is angry at Howard for leading her to believe that she was the cause of his mother's condition.
- "The Roommate Transmogrification"- Bernadette reveals that her doctoral dissertation was accepted, and that she would be receiving her PhD, much to the happiness of Howard for her (even though his friends mocked him that his fiancee was a doctor and he was not). She was also employed by a large pharmaceutical company who would be paying her "a butt load of money", she later on told Howard that she volunteered to research premature ejaculation stating that "neither one of us has heart disease". She also bought Howard a Rolex watch with her new money, which then prompted some role reversal, as she took on the role of a rich husband doting on his trophy wife. The next morning, Howard visits Sheldon and Leonard, stating that he had stayed up all night fighting with Bernadette because "she gave me a beautiful watch", much to the confusion of Sheldon.
- "The Shiny Trinket Maneuver"- Howard was upset to learn that Bernadette dislikes and feels uncomfortable around children. However, she has agreed that when they marry she will work while he stays at home to raise their kids.
- "The Stag Convergence"- The guys throw Howard a bachelor party that does not include strippers at the request of Bernadette. During the toasts Raj tells everyone stories about Howard losing his virginity to his second cousin, having group sex with a Sailor Moon girl at Comic Con, and Leonard and Raj paying for a Jewish role-playing prostitute in Las Vegas (to cheer him up after he was dumped by Leslie Winkle). Wil Wheaton records it all and uploads it onto YouTube. Bernadette picks Howard and Raj up since they are drunk and is mad at both of them after seeing the video. She is wondering how she can marry a man that she doesn't seem to know. Howard shows up at Bernadette's apartment and gives Penny a message that he was sorry, that he also doesn't like the man he used to be and that the man Bernadette knows is who he is because of her. Penny gushes that that was the most beautiful thing she had ever heard and that it came from Howard of all people. Bernadette hears him and tells him that the wedding is not off though that she is still mad at him. They all end in a group hug.
- "The Launch Acceleration" - Howard finds out that NASA has canceled his flight to his relief. After his flight is rescheduled to before their wedding, Bernadette tells him that she won't stand between him and his dream and that they can be married after he returns though Howard tries every excuse to not go on the flight.
- "The Countdown Reflection"- In the beginning of the episode Howard presents Bernadette with a necklace with a star shaped pendant. As he is putting it on her he says that she will have to return it to him immediately so that he can take it with him to the International Space Station so, upon his return, she can have a star that came from space to which he says "Take that, every guy who's ever bought you anything!" This is also an important episode because they are also married. The officials at City Hall say that they can only wed three more couples that day (and there are many people ahead of them in line) and they do not believe Howard's reason for not being able to wait until Monday (he is leaving for Russia on Sunday to go aboard the International Space Station). They decide that their friends will get ordained and will marry them. Bernadette yells quite a bit during the ceremony (reasons ranging from Howard's mother interrupting to Sheldon attempting to say his part in Klingon). Once the ceremony is complete the two are happily married. The ceremony is planned so that the satellite taking pictures for Google Earth will take their picture on the rooftop of Sheldon, Leonard, and Penny's apartment building as they have their first kiss as a married couple.
- "The Date Night Variable"-. Bernadette insists that Howard tell her mother that they were moving out of his mother's house though Howard told his mother that they were reconsidering the move. Howard considers remaining at the International Space Station rather than facing the two women in his life that he had lied to.
- "The Re-entry Minimization"- Bernadette wants time alone with her new husband and asks the gang not to be at the airport when he arrives. While at home as they settle in the bedroom for a belated honeymoon, Bernadette falls asleep due to her allergy medication.
- "The Holographic Excitation"- Howard and Bernadette go to the comic book store dressed up in costumes as Smurfs.
- "The Habitation Configuration"- Bernadette gets Howard to move his stuff out of his old room. Even though he does do it, she doesn't want her husband to break his mother's heart and they go back to spend the night there.
- "The Cooper/Kripke Inversion" - Howard spends a lot of money on a 3-D printer to make a mini-Howard and mini-Bernadette. She loves them until she learns how much they spent. She takes him off their joint checking account until he can learn the value of money.
- "The Spoiler Alert Segmentation" -- Howard and Bernadette go to see a Cirque de Soliel show and, inspired, injure themselves afterward attempting extremely kinky sex. As they recover, Howard learns that his mother has been doting heavily on Raj, in effect treating him as a surrogate son and won't let him out of her house.
- "The Deception Verification" - Bernadette must deals with the effects of her mother-in-law's estrogen cream after Howard absorbs at lot applying to his mother's back. He becomes very moody, cranky and effeminate.
- "The Workplace Proximity" - After Amy starts working at Caltech, Howard mentions that he wouldn't want to be working with Bernadette all day long. Sheldon repeats his comments in front of Bernadette who confronts Howard and then tells him not to come home after he lies about it. Later they apologize to each other. Howard promised to turn over a new leaf and make her his priority, after he finished the new Batman game with Raj making Bernadette mad again.
- "The Romance Resonance" - For the anniversary of their first date, Howard writes the song "If I didn't have you" to be accompanied by his friends. Bernadette misses the date since she has to go into quarantine so Howard brings his piano to the hospital and everyone sings it to her. She finds the song amazing.
- "The Gorilla Dissolution" - Their relationship is a bit strained after Howard's mother breaks her leg and they have to move in with her to take care of her. Their solution is to get a nurse to take care of her and they realize that they are experiencing what it will be like to care for a baby, if they had one.
- In "The Hook-up Reverberation ", Raj tells the gang that Stuart didn't get enough insurance money to reopen his store. The guys decide to give him the money and were enthusiastic about owning a comic book store. Howard mentions an investment opportunity to Bernadette who immediately says "nope". They are saving up for a house and it sounds "risky." Howard then mentions that he used to go to the comic book store with his Dad and Bernie changes her mind even though she knows he made up the story. They propose to Stuart to give him the money for the comic book store which Mrs. Wolowitz has already done upsetting Howard.
- In "The Septum Deviation", Raj learns that his parents are getting divorce lawyers. It seems over the years they did not communicate and let a lot of little things boil over until they hated each other. Bernadette worries about their marriage and Howard is reluctant to describe what bothers him about Bernadette. Howard has been through couples' therapy (with Raj) and one trick is to describe what one loves about the other. It starts out fine, but then get petty as they sarcastically tell each other what bothers in pseudo-supportive terms.
- After the death of Howard's mother, they worked on her house and moved in leaving Bernadette's apartment in the latter part of season 8.
- Bernadette wants to redecorate the house to remove anything she finds depressing. Stuart moves out and the redecorating is accomplished. In the episode "The Valentino Submergence", she mentions that she is pregnant with their first child to the rabbit they rescued. In "The Positive Negative Reaction", she tells Howard the news. Howard is at first freaked out a the responsibility of raising a child and then embraces the future as much as Bernie does.
- In "The Big Bear Precipitation", Raj is getting too personal with his interest in Bernadette's gestation. They ask him to back off. They all get to hear the baby's heart beat, while Bernadette is getting extra emotional due to her increased hormone levels.
- At first Bernadette is not excited about all the baby preparations which makes her think that she'll be a bad mother. A discussion with Raj's father who is an OB/GYN, makes her feel better. In "The Cohabitation Experimentation", they have a sonogram and don't want to know the baby's gender. Raj knows to their discomfort and the couple has a battle of conscious on whether to find out. Also Raj is way too involved in the pregnancy including going into her OB/GYN exams. After feeling the baby kick, Howard runs out and buys an expensive crib and a minivan.
- In "The Birthday Synchronicity", Bernadette is rushed to the hospital and gives birth to their daughter Hallie Wolowitz. Howard helps Bernadette during the time she was in labor and trying to calm her down. Howard felt bad that she was in pain.
- In "The Proposal Proposal”, when Sheldon calls about his engagement to Amy, Howard tells Bernie who discovers that moment that she again pregnant. Howard thinks that she is crying about the engagement. When she tells they start several rounds of "No" and "Yes" with both of them wondering if they can raise another baby.
- In "The Explosion Implosion", they learn their unborn child was going to be a boy as Howard is worried he won't be manly enough to raise a boy. After a talk with Sheldon, he overcomes his worries and prepares to raise another child with his wife.
- In "The Neonatal Nomenclature", Howard gets upset that Bernadette has already decided that they are going to name their son Michael after her father. The gang tries to help Bernadette get into labor and when she does she had her son and they name it Neil Michael Wolowitz after Neils Armstrong, Diamond and Gaimen. Bernadette still insists that he'll be called Michael.
- In "The Athenaeum Allocation", both parents seem to want to stay at home with the kids, but individually they find it exhausting and really don't want to give up their carreers.