double standards

my boyfriend had sex with 6 other women before me. he was my first. he cheated on me (got head from another girl) while we were dating. 
I suggested an open relationship and he said ok. now he's saying it bothers him. I'm frustrated because while he can do whatever he wants, he can't stand the thought of me being with someone else. what do I do? I don't necessarily want to be with anyone else because I love him but the unfairness is making me mad.