Another typical case when the guy ends up with his sister's best friend. They get married but the sister doesn't leave them alone and is always knocking at their door cause she misses the old times. The guy says once his sister knocked at their door at the wrong time and found out they like to have sex in front of the webcam and from that moment they started to do it as a threesome. The girls told him that they used to have threesomes with other guys but because he was her brother they never thought of having one with him, they thought he might didn't like the idea. By the way, the sister is the one all over the guy, we guess this one is of their first times...