Ever since your dad re-married, he has been so much happier. Of course, living with a new family isn’t always easy. His new wife and her twin daughters take up a lot of space and you have been used to living in your big house alone with dad. Having sisters around all the time can be a bit of a drag. At least for most people. In your case it isn’t so bad though. Your new twin stepsisters are cute, just turned eighteen and love nothing more than running around their new house in tiny booty shorts and tank tops with no bra. At first you thought they were just being young and carefree, but you started to notice the way they look at you when your parents aren’t home. The twins may look innocent, but they know exactly what they are doing. They love to tease you with glimpses of their perfect round cheeks and perky nipples. One day when dad was off on a business trip and their mom was out shopping, the twins caught you looking. They want to know if you like what you see. Would you like to see more? What guy could turn that down? You watch as they undress each other, noting how their bodies are identical and perfectly ready they both seem for a good fuck. You watch as they spread their legs and masturbate side by side. “Join us,” they bed. “We want to see your cock.” You stroke yourself while watching the twins rub their tight little pussies. They cum together and you are almost there yourself when you hear their mom come home. You all scramble to get dressed in the nick of time. “No worries big brother,” they whisper together. “Next time you can do more than watch.”