This story doesn't involve sex, but since it is directly related to my endowment I thought I'd post it anyway.

Was at a party a year or so ago, sitting out on the veranda late at night with a few others, and a tipsy fringe conversation turned into a discussion about penis size.

I happen to have quite a large one, especially girth-wise, and mentioned that I was in the top percentile of all men — a fact I'd only discovered the week prior. Arrogant I know, and something I probably would've held back if sober, but...

One girl and her boyfriend got particularly inquisitive/sceptical about it, and I quietly offered to show them... to my surprise, they (well she) agreed.

We go to a secluded, dimly-lit area of the backyard and I whip it out for them, 90% hard already due to the circumstances. A few seconds later the girl actually crouched down and grabbed it to feel its circumference for herself, giving a little gasp as she put her hand around it (it only reached about three-quarters of the way around my shaft). That part was particularly hot... I love watching girls' reactions. Then she glanced up at me and absent-mindedly stroked it a few times; basically gave me a semi-handjob there and then in front of her BF, no more than 10m away from all the other guests, smirking like a Cheshire cat.

After that we made out way back to the party and spent the night separately. I never saw those two again after the party (they were friends of a friend, I didn't know them directly), but that moment will stick around in my memory for a long time. No clue what the BF got out of it... whether he enjoyed his GF ogling another man's cock, or simply felt he had no choice in the matter.

TL;DR: Bragged about and showed off my penis to a couple at drunken party, got a quasi-handjob from the impressed girl.

EDIT: That flair next to the post title is incorrect. No idea how it got there. My real measurements are beside my username.