cheating. 😒

Wanna forgive my SO for cheating.. Because I want us to work out.. And he never had sex with them, just talked about it a lot. Asking to hook up and for nudes. From 5 different girls.. 
I wanna forgive him... I just don't know if I can. I can't quit thinking about those messages... They replay in my head over and over and over. 
I'm just scared he'll do it again. I've put 3 years into this relationship. I gave up so much for him.