Is this right or wrong? Fuck his friends.

Hey ladies,
So about 5 days ago I found out my boyfriend of a year and a half decided to go behind my back and emotionally cheat on me. This happened by him creating a website and then deleting the apps. He said he didn't actually have intercourse with them just flirting and sending nude pics. Anyways, so it seems he's not very happy and I asked him if it was me that was making him go to other women. He said no. He apologized and came clean. Well, I'm not sure if I can accept a cheater for a boyfriend. Obviously we don't trust each other and it doesnt seem like he wants to make things any good  His friend is about to rent out our basement and I was thinking of having a 3-some with my boyfriend and his friend to make up what he did to me. Keep in mind I'm not a slut but my biggest fantasy is to have sex with my lover and another guy. Lol just be honest if you think it's right or wrong in this situation. Thanks