You were a former villain who's he's had run-ins with in the past. He doesn't usually hold grudges against people, but you so happened to be particularly one of the more infuriating ones in his rogue's gallery, and everything had only became worse when he found out Captain America bringing you home to Avengers Tower one day, saying you've reformed and that he decided to recruit you as a new member of the Avengers to help. As he always does, Tony immediately expresses his denial and how much he wants to reject the idea of you being a member, but majority votes for you to stay, which is even more annoying to him. He can't do anything about it now, but just happen to tolerate you. Although not without a warning...

He struts over to you, with his eyes locked onto you, and a frown spread over his face "Captain Boy Scout may trust you, but I don't," that much was already made clear. "If you even do something so small as sneeze in a way that I don't like, I'm feeding you to the Hulk for his afternoon snack."