Yep! This is THAT thread concerning the first time a woman spread her butt cheeks for you or (ladies only for the next one!) you found yourself with a dick up your butt.
I'll start. I won't say how old I was the first time but the woman that took my virginity was in her late 20's. I think I was so damned shocked that my dick was in a girl's pussy that I must have had a look of shock and panic all over my face. I think I lasted less than a minute. After that very first time I had 7 great orgasms inside her that afternoon. The last two were with her lying on her back on the side of the bed shocked that I was still hard enough to fuck her for orgasms nos. 6 & 7. She called me over to her hosue about 2 weeks later for another round. I think I told my Mom I was heading to noon mass while grabbing the car keys. I doubt she believed a word I was saying but she wasn't about to ask where I was REALLY going for fear I'd tell her and dash her dreams of raising a good Catholic boy. Thirty minutes later I was hammering her and hoping for orgasm no. 3 when she rolled over and started spooning me. I sghed and wrapped my arm around her (looking for a boob to play with) as she ground her asscheeks on my dick. Next thing I knew her hand was guiding my dick between her cheeks. At first I thought "OK..she want's some doggy" but it wasn't 'that' hole. It turned out to be a much tighter fit and took a lot more time to get in. She was gasping and whimpering quite a bit more too compared to when she'd sit on me or spread her legs missionary and just let me slide on in. I was too much a novice to even comprehend that she'd just stuck me up her butt but it was a reality as soon as she rolled up in a doggy position and guided me back in. I could see from that angle and was shocked that you'd ever wanna have your dick up a girl's butt..ewwwwwwww!!! I liked the way girl's butts looked in jeans...her's was fun to grab when I was humping her pussy....but damn dude...all I could think was that my dick was gonna be nudgin' up and into the next bowlfull of..well...you know...I kept waiting to see my dick all smeared with..well..you know and just kept myself balls deep hoping I'd shoot and could get the Hell outta there and go wash it off! I did just that. When I came back she had this look of "Boy you don't know what I just did for you!" on her face. Years later...after I learned that stickin' your dick up a girl's butt was special I appreciated her gift but still felt a bit queasy the next time I get in there. Since then I do it with a sense of "this may be the last time you're stickin' your dick up a girl's butt" and try to savor the moment and the experience.