Jerking Off In Front Of My Girlfriend And Her Sister

I live with my girlfriend Tina and her sister Beth. My girlfriend Tina loves watching me jerking myself off and coming. It was a Wednesday afternoon a couple of weeks ago and I was laying nude in the middle of our bed and I was stroking my dick and Tina was sitting on the bed to my left stairing at my cock as I stroked it. After about five minutes had gone by there’s a knock at our bedroom door and Tina told her sister Beth to come in. Beth opens the doors and sees me stroking myself and she gets a huge grin on her face and Tina tells her to sit down on the bed. So now Beth is sitting to my right watching me stroking myself and she says that it looks like I’m really enjoying myself. I asked her if she was enjoying watching me. She said, I’ll never turn down a chance to watch a guy jerking himself off. Then Tina suggests that Beth should fondle my balls. Beth asks me if it’s ok, I told her sure go for it. So as I am stroking my cock she is fondling my balls. This goes on for several more minutes and when I came it shot into the air and the first rope of cum landed in Beth’s hair on the right side of her head and in her ear. The second rope of cum landed on her cheek and nose then the third landed on her sweater on her shoulder. Beth was stunned and Tina seemed excited and she leaned down and took my cock into her mouth and began sucking my cock. Beth then left to go wash up. Later Tina told me that her sister had gone and took a shower and masturbated herself to two orgasms. Now I frequently get to jerk off in front of Beth wether Tina is there or not. I’m kinda hoping that Beth will suck my cock in front of Tina, Beth sucked my cock last yesterday while Tina was taking a nap.