White Guy with Dreadlocks
This person was first mentioned in "The Helium Insufficiency" when Howard, Penny, Bernadette, Stuart and were using Amy's phone to scroll through Tinder (Assumption: The app was never named in the show), trying to find a new boyfriend for Amy, depite her protests of the gang using her phone.
Amy had recently broken up with Sheldon, and while talking about it with Penny, Bernadette brought up that Stuart had recently began using a dating app. Stuart noted it had "changed his life" after going on two dates.
Amy protested against the gang using because, as later shown, she didn't want them to see any previews of her incoming messages, from David, the guy she's been seeing. She then reveals that she has seen 3 guys since she broke up with Sheldon, much to the dismay of Stuart, who only saw 2 girls.