I think this is a great question (i.e., the OP).
i'll toss in a gay perspective, and also being a guy who was married to a woman.
i grew up in a strict religious culture where sex was verboten prior to marriage. my wife and i were both members of the same belief system and were both virgins, so we were each others first. i was young and inexperienced, and if i take what she told me at face value, she never masturbated, at least using penetration. i, on the other hand had a ton of penetrative experience as a bottom lol, i had been putting things in my rectum from an early age, i had discovered it as a sex organ way before my penis.
i was so inexperienced that i actually missed the first time. Yep, literally missed my former wife vagina I.e., i didn't get in). i had nothing to compare to, and pretty much my first experience was humping. She was quite gracious about telling me that i hadn't actually gotten there, and even though i had a very quick orgasm, i recovered pretty quickly. There was no question in her mind that i was a virgin.
We pretty much discovered together after that. She introduced lube to me and guided me in the second time. We got plenty of practice on our honeymoon. i was so ignorant about female anatomy though. Since we were both new, orgasm was pretty easy for both of us after she opened up. But after about a month of marriage, she broke down and cried and accused me of not caring because, apparently, i was missing the mark. It wasn't that i didn't care, but i was clueless about what a clitoris is, where to find it or how to stimulate her. i learned from that moment though, i hated her tears and disappointment.
It's kind of interesting how i got really good at giving my wife multiple orgasms, but over time she was disappointed by that. i trained myself from those first tears to never orgasm until she had. She later reached a point in our marriage where she expressed the wish for me to just "take her" without regard to whether or not she had an orgasm. i never got to a place where i could do that, that was about 20 years into our marriage. Now, after years of divorce, i get her need to be "taken." We were both bottoms and both sort of sub in nature.
i think a lot of notions of virginity are born out of religious culture, mine and my former wife's sure were. Virginity (especially a woman's) are touted as virtue. In the religious culture i grew up in, virginity and virtue were practically synonymous. my religious culture was decidedly patriarchal and sexist in structure, so the primary and underlying emphasis was a woman's virginity. Today it's kinda hilarious for me to think of these guys blowing themselves up in the name of their god in hopes of getting 80 sexually inexperienced women as a reward. i am a loss to think of any activity that is better when ignorant and inexperienced?
Now days i think the whole notion of a guy wanting a virgin is immature at best. How developed is the ego that needs someone inexperienced in order to feel fulfilled?
As a gay bottom, i had a ton of practice taking things into me before my first penis. i so agree with Susie, "it's practice."
i'm a member of a gay discussion forum, and by far most Tops want an experienced and opened bottom. The idea of a "tight" hole is pretty much the fantasy of inexperienced guys. We actually do surveys and both Tops and bottoms mostly seem to want experienced partners, not virgins.