I dont have the answer but I’ve wondered about it alot.
I’ve had anal intercourse with 4 women. In each of those relationships anal sex ended up happening alot more often than vaginal. At the time I never thought to ask Why do you like anal intercourse? Although we did discuss our desires.
The first woman was like me, anal obsessed. It was for her utterly taboo, naughty. Her family was very strict and religious, she was the black sheep. She had such a fetish and desire to have her bottom exposed, spread, rimmed, fingered and fucked and loved talking about it before during and after. We never again had vaginal sex after we first had anal. And she loved returning the favor, loved spreading and exploring and penetrating my bottom.
The second woman was quite different. When we first began exploring one another, she usually lay on her stomach or straddled me 69, so her bottom was often what I was looking at. Her enjoyment was very physical, she wasn’t into the naughty or taboo aspect, talked easily about bodily functions, and was perfectly comfortable letting me explore her anal area early in the relationship. Rimming and fingering made her very happy but having a thick hard cock pumping in and out of her anus made her groan in a guttural way. She would play with her clit and always tried to time her orgasm with mine.
The 3rd woman had zero anal sex experience or desire before she met me. She later told me she’d shamed a previous boyfriend for touching her anus during sex. The night I met her was very alcohol fueled and we had drunken messy sex that we didn’t much remember when we woke up. Fortunately we laughed it off. Very hungover. Half asleep on her stomach I looked and realized what a gorgeous ass she had and started caressing it. She moaned and said it felt good. Don’t know where I got the courage but I put my thumbs along her bottom crease and said “can I have a look in here?” gently pulling her cheeks open. But before I got a look she pulled away saying “no, not there!” in a teasing way. She must have thought about it and realized it was something exciting because the next time I saw her we were totally sober, skipped dinner, headed straight to the bedroom, and not long after removing all our clothes she handed me a vibrator and said in a lusty voice I still remember “I want you to put this in my ass.” For the next year her bottom was never ignored in the bedroom and usually ended up with KY and my cum in it. To this day I’m still not sure why she switched her opinion about anal sex.
The 4th was a very sweet, conservative looking and dressing woman, a librarian actually. On our first date I wasn’t even sure a kiss was even a possibility. How looks can deceive! The first date ended in bed to my surprise but I was still a bit hesitant. On our 2nd date she asked for a massage when I drove her home. Naked and facedown on the bed, she seemed to be enjoying my hands and very slowly I began massaging her very cute bottom, gently stroking her cheeks and spreading them because I wanted to look at her anus. Something I didn’t even consider at the beginning of our first date. She moaned louder. I remember holding her bottom wide open at one point asking “are you ok?” “Mmm yes” she said. “Cause I can see pretty much everything right now” I said. “I know” she whispered. Not long after I began to rim her for the first time which got us both more excited. I straddled her so we could fuck and began to push my cock into her pussy. I wasn’t thinking about anal intercourse since we’d only had vaginal intercourse once before anyway. As I started to push into her she said “no, in my ass”. “Really?” I had to ask (I was surprised plus we had no lube just the saliva and pussy juices). “Yes fuck my ass” she said panting. We were both quite worked up at this point. When the time came I asked if I could cum inside her and she said yes. That was the first of many such times, though she never said why she liked it so much. And she said no one had ever touched her asshole although her former husband had wanted to have anal sex but she didn’t at that time. We had vaginal sex occasionally. She loved cunnilingus. But having her bottom licked and fingered and fucked made her very happy. Usually she liked having me “prepare” her by fingerfucking her anus with 2 fingers and vaseline. She would always ask me to do that with a big grin on her face.
In the end, why we have our desires is always pretty mysterious.