Bobby is a character in Young Sheldon and is portrayed by Matthew Josten. He was a student at East Texas Tech in the 1990s.
He had borrowed Sheldon Cooper’s room in Hudson Hall and had sex with Diane. When they finish, they exist and are greeted by Sam and Sheldon. When Sheldon mentions an all-nighter, he goes along with it and walks away. (An Expensive Glitch and a Goof-Off Room)
He appears again when Sheldon becomes a resident adviser, rebelling against Sheldon making Sheldon having to turn off the hot water, they later duct tape Sheldon to a wall. (A Resident Advisor and the Word 'Sketchy')
He appears again when Paige is at a party and tries to give Paige a cup of beer, Sheldon comes in when he tries to make contact with Morse Code and sees Paige before he gives her the beer. (A Frat Party, a Sleepover and the Mother of All Blisters)