I love my boyfriend but I'm curious about girls...

I've been in a relationship for 3 years and he hasn't always been loyal to me...he makes my cry alot...lately and for few years I've been curious about what it would be like to be in a relationship with a girl...lately I find myself just imaging myself with a girl...I'll see a pretty girl in public and just get sad and jealous.Ive never been with or talled to a female before in a relationship manor but I am more physically attracted to females...I love the feeling of being intimate with a man but I just don't know...I don't feel my family would accept my being with a girl. I love girl on girl porn and the idea of spoiling someone.am I wrong...what should I do?