My ex broke up with his ex for me they were together for a year n a half n me n him for just seven months , now he's thinking of going back to her because we kept arguing and he said he couldn't take it anymore . Thing is he told me that he hated her and that they argued all the time. After we split he slept with her 3 days after after her tesxting him for sex! Two main things they have a child together and they LIVE IN THE SAME BUILDING AS ME :-( please help me explain why he's going back to her I'm so hurt x

Remember how he broke up with her to be with you? Well, now he's broken up with you to be with her.

I'm sure he's also telling her that he hates you.

He's going back to her because (A) he can; and (B) that's how he operates.

Yeah your right there just seems like the last months have been a waste she put me through so much stress that now I'm on anti depressants and I've gone off the rails a bit . I am doing the no contact rule and thank fully I haven't bumped into either of them on the stairs which is good , I just keep finding myself asking why why why :-(

When he was cheating on her with you I'm sure she was asking herself these same questions.

Sometimes what goes around comes around. I believe in karma.

Can you move?

He wasn't cheating on her we got together after they had broken up . I can't move but I'm certainly looking into it :-)