Glenn is Bernadette's former professor and ex-boyfriend.
Glenn appeared in "The Love Car Displacement", in which he bumped into Bernadette and was introduced to Howard. He was going to do a panel on global warming, entitled "Remembering Snow: A Look Back", for the Institute of Interdisciplinary Studies’ symposium on "The Impact of Current Scientific Research on Societal Interactions". He didn't talk a lot, but Howard and Bernadette discussed him extensively. According to Bernadette, Glenn was one of her professors in university, and, subsequently, they dated for a year. Howard is intimidated by his height and his assumption of Glenn's male anatomy (penis), and is concerned he won't be able to pleasure her to the extent of which Glenn did. Later, he offers to drive Penny back to Los Angeles, much to Leonard's horror. Because of his use of the name "Bernie" for Bernadette, Howard has used this nickname since "The Love Car Displacement".