Flating with two guys and girls. I have a gf and what I tried to do was to have sex with my gf with a used condom with cum already. It was a thought for a few months but I decided to go ahead. One of the flatmates had sex with his gf I picked up the condom and poked a few pin holes. When my turn came to have sex with my gf I rolled up the condom (was difficult as it was used already so had to carefully roll/pull it up).
It kinda felt gross my cock submerged in someones cum but I got a hard on. And I final insert my cock inside her pussy and I could just think the cum coming out into her pussy which was not mine. and I fucked her good and then I came into the condom too which must have leaked out inside her.
Havent tried it after that but it was great experience.