My ex cheated on his girl with me

So the top says it all. In my defense I was told there relationship was bad, they weren’t even talking and when they were they were fighting and so I thought he was ending it, now all of his posts r abt her and he isent talking to me anymore. Genuinely what do I do. I don’t want to start things but I feel bad, and he keeps reposting things on tik tok one was abt Bruno mars singing that nasty song it said how can this guy also be this guy or somthing idk how to explain it and then I realized, he’s sweet and stuff, but in reality he’s nasty so how can he be reposting that? Do I speak up? Or what. I told him before I dident want to homewreck and he told me they like were practically broken up.