Go full-screen for better viewing.
So, Withered Bonnie still is jealous of Toy Bonnie and decided to slap him in front of everyone else (not exactly everyone ofc. BB, JJ, Endo 02, Puppet, Golden and the shadows aren't there but you get the point). Of course Toy Freddy wasn't going to stand around and let his best friend be slapped by some rabbit that clearly cares only about himself and complains about how awful his life is, like, bro, look at Mangle, she got it worse and you don't see her complaining about it. The reason why Toy Bonnie's face went dark was because he remembered what his parents did when they found out he liked both guys and girls while he was alive. Foxy was surprised at the sheer anger of Toy Freddy because he has never seen someone like him go off like that at someone. The reason why Withered Chica had the worried emote was because she knew something was going to happen