Mum does graphic design stuff for an advertising company. She only actually goes in to work occasionally; she does most of the work from home and send... in her designs over the internet or by courier. That means that normally she is home to look after Angie during the day. Today Dad wanted us to take Angie to daycare for the day on our way to school. Dan offered to drive us to daycare then on to school, provided we didn’t make him late for his first morning class. Dad left for work while we were. I then lowered myself into Sam’s cunt and started a slow pace of fucking her. I was sucking on her nipples as well as kissing her. In between, Joan was doing the same of playing with her nipples and kissing her.I felt Sam’s cunt muscles clamp down on my prick and again she sought permission to cum. Again, I kept up the pace of fucking her as I again wanted her to ride the crest before succumbing to the orgasm. I held, and held and then allowed Sam to cum. She was bucking against my prick and. Our parents addressed one elephant in the room, and Wendy and Bill addressed another. “So you are both OK with them being incestuous?” Bill asked. They both looked at each other and gave each other a kiss. “Wendy, We're brother and sister too,” Jim replied. Then I thought their jaws were about to drop. “Holy shit. You two are incestuous too?” Bill asked. “Yes,” Maria replied. So I think we all felt better about our relationship choices. I mean you yourself don't regret it, but you still gotta. I walked up to the window as he asked for directions to a place in town I happened to know, and as I stood pointing and looking in the direction I was pointing to, he took his cock out and started to wank himself.When I saw it, I froze and realized as I looked around to see I was on my own, 'It's OK', he said, 'it feels nice', his casualness and easy manner threw me, I knew what he was doing was wrong, but I had seen it before, and besides, I was curious, so felt no fear or the need to run away.