This kind of lust are common. Some woman might think that if let other bonk n in the end, nothing happened, might as well to let their own relative bonk if there is a chemistry. We now in a world of gay n lesbian, incest also might be the next hot thing.
It will be consider incest but from another view, it is just like a normal sex between two person. I even think that if one day, my cousin asked me to bonk her as she is single (over 30), I would go ahead but of course, protection is a MUST!!!
