Bisexual Romance with Two Guys

I had a boyfriend, now we are friends because I want an open relationship and he wants to be monogamous.
But last summer, we started dating a friend of ours. He's very pretty, blond, green eyes, small, white skin, short stature, and my ex boyfriend has dark hair, is taller, and dominant.
I am very feminine. As a teenager I considered myself bisexual. However, they had only thought of themselves as heterosexual so far.
My ex boyfriend wanted to kiss our friend, one night at a gay club. They kissed, first they were shocked, but little by little,  something sexual and romantic began between the three of us.
I realized that I loved seeing two bisexual guys together. My fantasy would be that my ex boyfriend gave anal sex to him, while my friend gave me oral sex. Or giving oral sex to my ex boyfriend and my friend at the same time. They also really liked having marked roles, passive and active, dominated and submissive...