"Sorry, man," he said, "but I just gotta jerk off." I sat there as he shucked off his jeans and underwear and took his erection in hand and started to...stroke it while studying two pages of pictures of a "Miss, Mr.& Mrs. Nude Acres" contest. After a minute or so, I realized two things: first, my mouth was hanging open. The second thing I realized was that my own cock was hard and begging for release. Watching Jack stroke himself made me get even harder."Come on, Billy!" Jack panted at me. "Join. She then asked me to come and help.she then purposely put water on her dress which made her top transparent and anyone could see her tits and tight nipples. My dick was hard and my mom saw that and naughtily smiled. She didn’t even change. We had our breakfast and then she went to change. She came out only wearing a bikini. She even removed her pant. I was shell shocked. I asked her what she was wearing so she said that since it was hot and no one was coming so she wore that.She then came and. As we had done the previous days we would go into the shower block just off the beach to shower and change into tops and shorts. The men's and ladies shower blocks were attached to each other in the same building. I normally finished first and had to wait ages for Denise to emerge but that day I was more than surprised to see her standing there looking very animatedDenise immediately pointed to the ladies shower block and said there's a man in there ! I just barged past her and pushed the door. “It’s your mothers rule and it will make it very special I promise.” My mind was racing, I had certainly had conversations with my girlfriends about sex and all. Some girls I knew were doing anal, to avoid the risk of pregnancy but no one I knew had ever mentioned nor do I think would have thought of having a guy in both places at once. I had heard that the big negative to anal was that it could be painful and of course most girls first times at intercourse are also painful. So what did it.