Is said that family members should take care of other family member's needs and this is what's appening here. The mother didn't had sex for more than 3 years since her husband died when she found out her son and her daughter was having sex together behind her back she got hungry, if he was fucking his sister why he couldn't fuck his mother who was desperate for cock? The guy says this was one of their first threesomes, it wasn't easy even with his sister's dedicated help to make his cock stay hard.