I think many times we put far too much emphasis on putting ourselves into a category, Straight, Bi, Gay, etc. About ten years ago we met a man who my wife was hot for. He had years of experience in the Lifestyle and during our first MFM with him, he pushed his finger up inside my butt while my wife was sucking me and he was eating her pussy. It felt amazing and I shot a huge load. In the heat of the moment, I thought it was my wife's finger, something she had not ever done before.
After we were all finished and laying on the bed, catching our breaths, I told my wife that feeling her finger inside my butt was hot. She gave me a curious stare and the guy told us it was his finger. For several days afterward, I questioned my sexuality. On our next meeting with this man, we again had an amazing session, and after I asked him if he was bi. He laughed and said no, he found he cannot put his sexuality in a box.
He said that he is into whatever happened and felt good during sex and he had no boundaries. He told us he learned he is a hedonist, versus being any other term. I found that to be a good example and definition. I have sucked cock, ate ass, swallowed cum, and more over the years since. I have not ever looked at another man with desire, but in the heat of the moment, anything is possible and enjoyable.