I turned her around and pressed my cock against her wonderfully girly butt cheeks before pushing my rock hard shaft down to slide between her thighs f...om behind and rub over her wet, swollen pussy lips. My hands reached around and held each breast firmly, my fingertips caressing her nipples, alternating between lightly touching them and pinching them. I thrust my hips back and forth and felt my cock head rub over her swollen lips again and again. Vi moaned and ground her butt and pussy against. For now, I was The Intrepid Explorer: What's this? Feels like a left breast! Hmmm. Hefty little sucker! And what do we have here? Why, it seems to be a hidden cavern of some sort, its entrance protected by light undergrowth. Remarkable! Zounds! It appears to have its own heat source -- emanating from the interior of the cavern!For at least another 90 minutes, before I was forced by my kidneys to abandon the bed, I continued this potentially deal-breaking misbehavior.Amy got out of bed soon. A softly moan escaped her mouth. "Get your ass back in that chair.", I commanded as I looked back at my father. He looked on, humiliated, having to watch his son fuck his step mom after sucking his son's cum from her ass. Erin moaned loudly as I drove my shaft deep into her, thrusting harder and faster as i pounded her cunt. Whimpering slightly as I smacked her tits before pinching her swollen nipples, rolling them between my fingers. Moving my hands moving over her body, one moving up to her. As time went on, my cock would stiffen up a bit then soften. After awhile, I consciously tried to keep it just less than erect, but it continued to soften and harden on its own. Occasionally, I’d run my hand down my stomach and over my cock and tug on it a bit to “adjust” things. What I really was desiring to do was slowly masturbate there in the open. At one point my wife said she saw that a motorboat was going to cross in front of us. She tends to point them out even though they aren’t any.