You're sitting beside your super hot sister trying to concentrate on the movie but she's not wearing a bra... again!!! You start stroking your cock under the throw blanket, but she all of a sudden throws off your blanket & totallys busts you, cock in hand!!! Ahha!! you were jerking off! OMG what a perv you are. But big sis has a lot of different techniques to teach you to make it feel even better... she's had a lot of experience.... she also didn't expect you to have such a big dick! So just follow along to your sis as she tell you to play with your balls, spit on it and even insert a finger up your ass until you blow a nice huge load. uh oh... mom & dad are back!!! Act normal and cover up! Hope they don't notice the cum everywhere