This happened a little while back when my girlfriend (who is a hot MILF) and i went into a night club.
There was lots of patrons and we found ourselves sitting on a couch in a back corner and watching all the sexy woman walking past. My girl kissed me and whispered that she was horny and she started to rub my cock through my pants. I was a little embarrassed, but she then said she had no nickers on and wanted me inside her now.
She then proceded to sit on my lap undid my pants and pulled my cock out which was now hard and just impaled herself on me.
It was so amazing to feel how wet she was and then she slowly started to move her pussy and god that was hot.
A few people noticed that we seemed pretty close and looked flustered and she just kept going and whispered for me to cum inside her. I didn't need to be asked again and blew my load into her. she then reached down put my cock back in my pants and zipped me up, just as a male and female security people came and asked us to seperate.

We stood up and I still had a hard on in my pants, which the female security looked down at me and smiled. My girl then very cooly grabbed my hand and said ever so sweetly "thats ok we are finished " and started to head for the exit. Security followed us out and i can only guess that they saw us on camera or someone complained, however we walked out and laughed all the way home about how horny and awesome that was!