did you always consider yourself bi, or is it something that developed with time/experience/curiosity? what experiences did you have that opened you up to the thought of being with another guy?
My same-sex attractions was there at least from puberty, but I spent too many years trying to deny and suppress them rather than understand and explore them.
I had my first M-M experience with a college roomie. It was fairly tame stuff (masturbating together, showering together, sleeping naked in the same bed together). I was young and every experience was new. Just touching another guy's cock was electrifying. We never did kissing or oral or anal (that would have been "too gay"). My emotions caught fire and I fell in love with him. I was confused and in turmoil. I became needy and possessive which never has a happy outcome. The relationship ended badly and I decided to focus on M-F relationships instead. After that, I lived a completely heterosexual lifestyle for the next 20 years (although my M-M attractions never really went away). I had a number of meaningful M-F relationships with strong emotional and physical attractions. I eventually got married and started a family.
As others in this thread have mentioned, I experienced a significant change at midlife. It wasn't that my M-F attractions changed, rather my desire to suppress my M-M attractions changed. I sensed that windows of opportunity were closing and I needed to act. I'm not the kind of guy who would ever visit a gay bar, but the internet made exploration too easy. I didn't just wake up one morning and decide to start fucking guys in the ass. It started out small with gay chat rooms and watching online gay porn. It progressed gradually (over years) to include kissing, oral, anal topping, anal bottoming, and even mild kink. None of these steps happened suddenly - each took a year or more of acclimatization. It is an insidious process. It chips away at your resistance and perceptions of what is acceptable and even normal. It forces you to live a compartmentalized life as a coping mechanism. It also numbs your conscience. At one time I did feel guilt, but somewhere along this path the guilt disappeared. I don't know if that's a good thing or not.
During my 20-year period of heterosexuality, I would classify my attractions as 20 gay/80 straight. If I am being honest, those percentages have now shifted to 90 gay/10 straight. I attribute that to conditioning from a decade of increasingly intense exposure to gay porn and gay sex. I don't doubt that conditioning could also reverse those percentages. I had 20 years to explore my hetero side, and so now I am having these years to explore my gay side. And in similar fashion, I am experiencing a number of meaningful M-M relationships with strong emotional and physical attractions.
Although I keep my M-M attractions a secret, I don't consider myself a closeted homosexual. To dismiss my heterosexual attractions and experiences as inauthentic would be just as wrong as dismissing my homosexual attractions and experiences as inauthentic.
Even among fellow bisexuals, there are widely different viewpoints. Some bisexuals state firmly that they only want M-M physical gratification and are repelled by the thought of emotional intimacy/bonding/attachment with a man. M-M kissing is even too much for some. Everyone is entitled to their own views and feelings I suppose. However, my M-M attractions exist on both an emotional and physical level.
In my option, bonding is the normal and expected outcome of repeated sexual unions with someone (M or F) you find attractive. Humans are just wired that way. In fact, I think something is broken inside when that kind of attachment does not occur (I'm not talking about random hookups and one-night-stands here). I wouldn't want to be the kind of person who remains emotionally detached through intense sexual intimacy.
Above all, I have come to understand that bisexuality is not an easy path. Rather than providing the best of both worlds, bisexuality means that difficult choices much be made about which desires will be fulfilled which desires will remain unfulfilled (or only partially fulfilled). A lack of comprehension, understanding and acceptance of bisexuality exists in both the gay and straight worlds. Neither world feels like home. Both insist that bisexuals are just homosexuals in denial. The kind of support from the gay community is essentially to comfort bisexuals to help them understand they are really gay. The kind of support from the straight community is more akin to total rejection. It can all be terribly frustrating.