Reposting a rant I posted on twitter under the cut
I think P1 would be resentful and bitter to the world around him. He put up with mistreatment and abuse his entire life that he began to perceive everyone as an enemy that was out to get him. That's why he latches onto P2 so much - because P2 is the only one that he can guarantee won't hurt or lie to him. He wants to keep him as close as possible. At first, this was something P2 liked or even wanted. It felt good to feel like he was worth *something* in a relationship after the fiasco that was his ex-wife. Only, P1 began to become overly protective of P1, like forbidding him to go outside, or talking to other people that wasn't him. He was scared P2 would become Infected like them. It came to the point P2 felt suffocated just by being with him, and it grew into P2 becoming bitter and resentful towards P1. No canon interaction btw.
