Normally, it's a lot of work to get the person you want to have sex with into the room, so the pattern of being in the room from the beginning is quick to talk about. This logic is often a factor that leads to close relatives with mothers and daughters, but if it is a mature woman who is a total stranger, the hurdle is even lower. In addition, a worthy and caring woman is weak and erotic, and this is a partner who has no choice but to do it.