Adam is a minor character in Grand Theft Auto V.
According to her Lifeinvader account, Mary-Ann Quinn met Adam through a blind date set up by her swimming coach. After two progressively worse dates, she makes plans to meet up with Adam at Galileo Park near the Vinewood sign to "annihilate him on the bikes, see if I can locate a spine anywhere in that wimp!"
He is described through Mary-Ann's Lifeinvader posts as "generally tolerable, not married, not disgustingly fat, not super-rightwing and didn't scratch his balls in front of me. 7 out of 10." then a "cowed little momma's boy", a "wimp" and lastly "a dickless commitment-phobe" but these later derogatory descriptions are more likely a reflection on Mary-Ann's personality than any accurate description of Adam himself.
Events of GTA V
Trevor Philips encounters Mary-Ann and Adam in front of the broadcast station at the end of Mount Haan Drive in Vinewood Hills. Mary-Ann is found screaming at Adam who apparently wanted to break up with her, she says that she doesn't care about him and tries to make very clear that he is the one who is wrong in wanting to end their relationship. He doesn't say anything during the entire discussion, since Mary-Ann doesn't stop talking long enough to allow it and even orders him to be silent. When Trevor appears, he knocks Adam out by punching him in the head.
Adam appears in the following Strangers and Freaks side mission: