I grew up in a conservative, homophobic and religious family (they are Jehovah's Witnesses, could have been worse though).

As a kid whenever anyone said anything about me getting married to man I always said I wouldn't. People said I would change my mind, I never did.

I had crushes on other girls early but thought everyone felt like that about girls they wanted to be friends with. I started having sexual feelings about women when I was around nine. I thought I had accidentally given myself a sinful sexual fixation to women by looking at the images of the female reproductive system. I was scared my parents would find the biology book and understand the "lewd" pictures I had been looking at.

The kingdom hall (church) used to warn us about the temptations of homosexuality and the temptations of the opposite sex. I thought the temptations of homosexuality was real as it seemed self-evident that people would rather have homosexual relationships, I thought the reason the elders were warning about it was because it was a real risk that the human species would go extinct if the trend continued (they didn't explicitly say they human species would extinct but they talked about it not leading to procreation so I as child interpreted it as that). I thought I would do my duty and not have homosexual relationships but no one would ever be able to force me to be with a man and have children, I didn't care if the human species would die for it. I didn't really get why the elders bothered warning about the opposite sex though as it seemed super easy to resist boys.

I still thought I was heterosexual due the infallibility of the creator, homosexuals were just heterosexuals who had self-induced same-sex fetishes (nowadays I think JWs acknowledge some may be born with homosexual inclinations but that it shouldn't be acted upon). As I thought I was straight I thought straight girls were repulsed by the idea of being with men just like me. I thought even if the creator created all humans to be heterosexual we can still say no to being with males, we can choose being celibate spinsters instead, no religious rule against that (many biblical passages supporting celibacy, I used these to make my parents back off). I thought straight girls acted so illogical when they voluntary pursued boys, like they didn't understand it was allowed to be alone.

I was quite vocal about my anti-sex and anti-romance stance in my teenage so my classmates suspected me of being a lesbian. I denied it (as the creator doesn't make mistakes) but they didn't believe me because it was evident I wasn't into boys. I only knew one person who was openly gay in the school, the girls liked him but they didn't like me so they bullied me lot, not just because of the lesbian thing though, for the way I dressed (looking too much like a boy), and for being strange overall.

I had refused to wear dresses/skirts since I was a little kid. My parents were ashamed of me as it considered an abomination for women to dress like men. I knew I had to give in regarding that if I wanted to be JW but couldn't make myself do it so I never got baptized fortunately.

I thought the sinful part of homosexual relationships was the sex bit so sometimes I entertained the idea that I could find a woman to be in a committed relationship with and we would just not do the sinful sex. I realized it was much harder than I thought in my first relationship, my first girlfriend wasn't religious so she didn't really care if we failed to not be sinful.

There were JWs who said that being with someone of the same sex was like a human being with a pig. The "unnaturalness" of homosexuality bothered me a long time, members of the same sex can't reproduce so homosexuality had to be a perversion. I realized though straight women who don't want children would have to be on birth control, and that seemed quite unnatural too. In that case it seemed better to be homosexual and not need birth control. Also eternal life didn't really seem worth the cost if one had to live life avoiding everything that is fun, and I decided I was fine with being punished with eternal death. I stopped believing in the "truth" (JWs nickname for their religion) later and I'm an atheist now.

I don't have any hard feelings against JWs though. I was never pushed to experiment with boys by JWs (extramarital sex being a sin). I think people from more progressive families might have had been more pressured to be sexually inclusive in order to be nice, and JWs focused more on teenagers saying no to sex despite it not being nice.

EDIT: Being more concrete