This happened years back, when I was still in college, but while I was back in my home state for summer vacation. I was hooking up with my friend’s ex, the first girl I met who was kinky, and our kinks happened to complement each others – she was submissive, loved anal sex (I think more than vaginal), and had wonderful curves. We hadn’t done much besides some spanking and fingering, but there was a lot of talking, and while I was at college she had masturbated on Skype for me a few times.
We ran into each other in the city and were planning on hanging out that evening anyway, so she invited me over to hang out for a bit before whatever we had planned. She wanted to shower and change before it, so she went to do that, but, knowing my predilection for panties, left her black g string sitting on her pillow.
I got the hint, or at least suspected we were on the same page, and played with them a bit, smelling and tasting them, before wrapping them around my cock and slowly stroking myself with them, effectively teasing myself. After a bit, I looked toward the door and she was leaned against the doorway, stark naked, playing with her clit. After we made eye contact, she came over, took the panties, and started sucking my cock. It was the first time she had done it, and the first time I had a really great blowjob.
When I was about to cum, I told her, and she pulled me out of her mouth and told me to cum on her panties, jerking me off with them. When I exploded, it completely covered the tiny thong. She cleaned the tip of my cock, stood up, and slid the thong on, rubbing the cum covered gusset into her already wet pussy lips. I spent the whole rest of the night knowing her pussy was soaked with my cum. It remains one of my favorite memories to this day.
Source: reddit.com/r/gonewildstories/comments/70ai5f/mf_a_dream_come_true
Literally my top fantasy, lucky you!