My cock slips in easily, I start to fuck her - we are building a good rhythm when suddenly we hear footsteps. I stop my thrusting, Bunty doesn't stop ...at all though and continues rocking to and fro, then circling her hips. The tap tap tap of the footsteps outside continues, Bunty keeps gyrating. As I approach climax I place my middle finger on to her anus and gently push. She gasps, her ass is tight but the juice from her pussy does the job and it yields. My finger can feel my dick moving within. "I couldn't help it. I felt my face once again go red. In my head, I am screaming, "My God, I'm about to fuck my mom."As we turned to continue up the stairs, I heard a man's voice, "Betty? My God, it is you. Fancy running into you here of all places. And Bruce? I haven't seen you in years." Great. We just happen to run into Bob, one of my baseball coaches from long ago. And here we stand with Mom clinging to me in a little black dress that barely covers her ass while the front barely contains. They kiss, then go back to grinding. I stand back and watch. You don't know where I am, and it seems you don't care much either. You have found a drink yourself, and are still going strong. At one point ,the girl rubs your side, then your ass. You smile. Then he does it and you smile again. Then they both grab your ass together. She leans in and you kiss her gently, then him. You all embrace, and your gentle kisses turn into full on making out. Their hands explore your sexy ass over and over. I. Her nipples were covered, but her tits were so big they were stretching the fabric of the bikini exposing parts of her areolas. The bottoms were big enough to cover her pussy thankfully, but it was small enough that part of her bush was showing around the edges of the bikini. I knew that I wouldnt be able to spend the day watching my wife prance around a beach full of people wearing the tiny bikini, flirting with her sisters boyfriend… so I stayed home. The three of them left early in the.