Brazen!! Quickie behind my stepdad's back!! He could have seen everything!!

How bold was that?! We were just having dinner and I was about to move away from the table when I suddenly felt a slap on my ass. When I turned around, standing there was my stepbrother's best friend who was also there all day. I've already noticed that he had often and intensely stared at my breasts when I was only wearing my bikini. The fact that I wasn't wearing a bra under my dress was probably too much for him and now he wanted more from me. But not here at the table while my stepdad is sitting next to me on the sofa. He only needs to turn around once and he would catch us completely. But he didn't let up and was already starting to take off my dress. When he finally opened his pants, his already hard cock jumped out at me and I couldn't do anything else. He took me really hard from behind after I had blown him even harder and the fear of being caught grew infinitely. How am I supposed to explain that to my stepdad?! To make matters worse, I just couldn't help myself and moaned loudly to myself from these hard thrusts. I hope he didn't catch anything!