Most Helpful Guy
you shouldn't it's simple as that. it's morally wrong. you have have sex with other people who don't have girls who they are screwing around on.
just put yourself in her shoes. imagine how betrayed you'd feel and how f*cked up it is to have a boyfriend basically maintaining a relationship behind your back. also imagine what you'd think of a girl who was hooking up with your boyfriend. would you think much of her?
i know the temptation is great but just resist. do the right thing