For most of my life I considered myself to be 'bi-curious, but functionally straight'.
My dad was homophobic, to the point where he could hardly say the word 'homosexual', and couldn't discuss sex matters at all with me. Mom said dad had a bad experience as a child with a 'Baptist preacher' that affected his ability to discuss sex stuff, but no one gave me any details. Heck, for all I know maybe dad had a gay experience that embarrassed the hell out of him when he was a teen! Or maybe that preacher just drilled it into him that being Gay was horrible and a sin. Dad wasn't particularly religious, and didn't rant against gays. He just couldn't discuss sexuality issues at all. All I knew in my teens was that there was no way I could tell either of them that their only son had just had his first experience with someone else giving him sexual gratification, and that it had been another guy! I had pretty mixed feelings about it myself, and tried to ignore that one night as a one-off experience. Never got intimate with that guy again.
As I grew up, I did the expected thing and only dated girls, and only offered platonic friendship to other males. Yet I still found myself looking at some men with the same longing that I had for women - thinking that a guy was hot and sexy. And I did allow one other guy to pleasure me, one night. Then later, when I was in the Navy and one of my Navy friends came out as gay and got a discharge for it, I almost confessed to him that I found him attractive, and wanted to try sex with him myself. But I didn't dare come out. I couldn't risk my family finding out.
I married a nice girl and had a straight, monogamous marriage for 30 years, and we raised a lovely daughter together. My wife knew I had bisexual leanings. So for that time, my physical activities were entirely straight, though I would, in private, occasionally enjoy some MM fantasies.
I developed a female on-line personna and did some adult roleplaying as Ceera, but kept a very clear division between what Ceera did on line and what my real life could include. I made it very clear to any of Ceera's on-line friends that I was married and monogamous in real life, and that any on-line roleplaying was only that, and that all I offered between us in the real world was a platonic friendship.
In the last few years of my marriage, after both of my parents had died, I started covertly wearing women's underwear. My wife and daughter eventually knew, and accepted it, though my wife was a bit uneasy about me doing it.
Now my wife has also died, and I am single again, with no one to be held accountable to for my pleasures but myself. I decided to come out to my daughter about being bi and liking the idea of fully cross dressing. My daughter is 18, and accepts my choices. She even helps me to shop for girl clothes!
Since last July, I've been going out en-femme to a nearby gay club, and have been open to whatever might happen. Last weekend, for the first time in my life, I accepted an offer to 'go someplace and make out' from a guy, and took him to my home and my bed. It was my first time having sex while en-femme with another male. I... liked it. Pretty much knew I would. I think I still prefer women, but I'd date a man just as readily, if I liked him. So now I consider myself fully bisexual, with a preference for female partners.
I doubt I could ever be satisfied with trying to be a girl full-time, or with only having a male lover. I enjoy mating with women as a male too much. But I'm pretty sure that from here on out, I'll be working both sides of the street with my relationships. Maybe I can find a nice couple who likes threesomes? Who knows...