Why do I feel soo bad ?

• Well my boyfriend ( we weren’t going out at the time but , were friends w/ benefits ) Had sex with a girl while I was away in another country having trouble w/ my mom leaving me there and dad betraying me .

And one day I told him something bad and than he went out with this girl for a day in a half and than had sex with her . And now he regrets it and doesn’t even talk to the girl anymore unless she says hi bc he doesn’t want to be mean or rude .

But what do you say ? Am I stupid for letting him back in my life ?

Bc I really love him and don’t want to loose him for no reason ..

He was there for me all the time , Calling me everyday , and never let me down until that day he did that . He still called me everyday after that and told me he missed me and wishes to take that day back .

But , we promised to loose our virginity’s to each-other and than he went to do that . That was his first time .Now I feel so horrible like it was my fault , all I do is remember that day and I feel so bad . I can’t even look at that girl . My friend was part of it but ugh . I’m confused . Plzz Help .

Am I stupid ?