question about later in life besexuality

I was wondering if anyone could answer or direct me to a source that might help me figure out something. How does someone in their late twenties become sexually attracted to a straight guy after being strictly lesbian, but only with that one guy? And is still basically attracted to women? Is it psychological or hormonal, or both? A friend of mine said it was because I subconsciously wanted some guy to screw me to get pregnant, my biological clock. That can't be, because I don't want kids, and use 3 different methods of birth control.

I should mention that I've been an in the closest lesbian since I was 13, and that I dated guys in high school, not because I wanted to, but to

A: hide my feelings from my parents, who would've sent me to conversion therapy, like a friend of mine who came out

B: threatened with gang rape, like another friend who was accused of being a lesbian, and

C: trying desperately to be what other people considered "normal"

When guys in HS tried to kiss me, or hug me or try to get me to do other things, I refused, which led to accusations of my being frigid or being a lesbian. I used the excuse I was a good girl, and saving it for marriage.
When I was on my own (in college) I found my life partner, and we moved in together. She and I were a couple for several years, until she passed away. I didn't date anyone seriously for almost 2 years, I emotionally shut down any idea of another relationship I guess.

My partner and I had been friends with a married straight guy for a couple of years. He knew about us but kept it a secret, because I work at a job where I would get fired if I came out, and she was in the military part time, as was he. Last year his wife divorced him, said her kids were grown (his stepkids) and that she wasnt happy anymore, wanted him to leave. This past May we both started going out to do things together. We didn't call them dates, just going to the movies or out to eat, and have some good company together. One night we went dancing with some mutual friends, one of whom said straight girls would want to date him more if they saw him with me. I saw some women look, but he didn't approach anyone, and they didn't approach him. We kissed that night, and it didn't feel wrong like when I was a teenager.

He has some combat related injuries that give him back and shoulder pain, but is trying to not take narcotics. One night I could tell that he was hurting and told him I could give him a back and neck massage, like what I used to give to my same sex partner. I told him up front that it wouldn't lead to anything more though, and he was okay with that. I had him undress and lie on his stomach, and I undressed and sat behind his behind. After the back massage, I told him to turn over. He sat up as I leaned forward and we kissed again. One thing led to another, and we ended up making love. It was totally my decision, and although I didn't orgasm, it wasn't painful, and I enjoyed the experience.

Although I'm still attracted to women, I haven't acted on it, because I now have a relationship. I feel like I love him, and have orgasms with him, but don't know if this is going to last or not, because I don't know what caused this in the first place.

 

Thank you for the replies. Someone reading my question might wonder why I'm even
concerned about it. I know I certainly didn't think about why that first time. It was
almost exactly like the love scene in the movie "An Officer and a Gentleman". When it was
over, and I was staring into those eyes, I was to into it to think about anything except
us.
When he said to me, "I thought you said it's just a massage (when I asked him to undress) nothing more?" I replied, "I changed my mind", and that it was a woman's prerogative.

The next day however, was totally different. Because it was unplanned for both of us,
neither of us thought about birth control. I never had to worry about before. I was in a
panic. I swore that I would never ever have sex with him again. What eventually happened
though was that I starting using birth control, and slept with him again. I was curious
about whether or not my feelings the first time were just an isolated thing or not. I was
nervous at first, since this time it was planned, and there was a condom involved,
(which he or I had no previous experience in)and he sensed my nervousness. He was great
though at making sure my desire was there before we did it. The second time we made love I actually came, and it got better and stronger every time.

He was pretty inept when it came to giving oral, (as was I at first) but he takes
instruction well, and is now great at it, at least for what and how I want it.

I guess my concerns boil down to 2 things. The way I currently feel, unless he does
something really bad, something to make me not love him, I probably always will. The
problem is, I feel that sex is an important part of a romantic non platonic relationship.
I'm considering moving in with him, or even marrying him someday. What I don't want to
happen is a year down the road discovering I don't desire him anymore. That wouldn't be
fair to him or me. And I will NOT have a sexual relationship with him if I don't want to,
even though I love him. That isn't bisexuality, it's rape.

The other thing is, and I don't mean to offend anyone here who is bisexual, but all my
life I've thought being truly bisexual were kinda weird. By truly, I don't mean something
who actually wants to have sex either way, not someone like a friend of mine who lets her
husband screw her and then goes to have enjoyable sex with her girlfriend. I'm not condemning her, I understand that divorce isn't an option for her, but I just couldn't live like that myself.

I get being gay or lesbian or straight. To me, my desires weren't merely some choice I
made. I felt I was hard wired a certain way, and would never change. I was like a negative
charged magnet. Girls were positive charged, and boys were negative charged when it came
to intimate contact with me, repelling instead of attracting. It wasn't like I didn't like
boys, I did. I even thought I was in love emotionally with one particular boy, but after
attempting something found out emotions don't automatically lead to physical desire.

If some one had told before this happened that I, in my late twenties, would enjoy
having sex with a man I'd have said they were crazy. After it happened, I was worried that
I was the crazy one. In fact, when one of my friends found out, she was shocked, and said
"Ewwwwww" like I'd betrayed the sisterhood or something. It's the exact same reaction my
sister had when she found out I was a lesbian.

I actually told my friend, "sorry, I didn't mean for it to happen," which was stupid of me. She replied, "How could you?" which lead to another friend of mine saying nonchalantly, "How could she? You don't know? It's like when I assembled that hutch. Step one is remove the covering from the pieces, step two is to insert tab a into slot B, .." which caused me and someone else to laugh. She wasn't amused however, glared at her and shot back with "I know HOW it's done, I meant how could she let some guy just f--- her?" I went from remorse to laughter to hurt feelings very quickly. When she said that, it sounded so dirty. That word generally bothers me in relationship to sex, although a month ago when my guy was giving me foreplay I was so horny I just uttered without thinking, "Please, f--- me now, don't make me wait." I'm not normally into dirty talk, and it kinda shocked us both, but he was okay with it. Anyway, I didn't let him "do" me, if anything it was more like me doing him. I told her that I didn't tell them this so they could make me feel bad, I wanted some help to deal with it, to understand it.

Some of the advice I got was:

"You had too much wine." While it was true that we shared one glass of wine, I wasn't
drunk. In the past, even on the rare occasion I did get really smashed, I NEVER had sex
with a guy.

"You felt sorry for him, it was sympathy or comfort sex." It's true I did feel sympathy for
his situation in life, and he had sympathy for mine. Even though I wanted to provide him
comfort for his physical pain with the massage, I have a hard time accepting what happened
afterwards was just comfort sex. I did have him undress, and so it I, but it was just
because I've only ever given a massage one way, like I did with my partner. For me, sitting
behind someone is easier than standing alongside the bed anyway.

Anyway, sorry for being so long winded. Just like birth control, my health plan
doesn't cover psychoanalysis, so I didn't know where else to turn. My boyfriend knows of my
concerns, and can't help with the why, because he's always been straight. He says he loves me though, and is willing to try to make things work. I guess I shouldn't obsess over this. I'll try to move in with him, and see where things go from there.