My wife said that she never refused her brother when he wanted unprotected sex because his teenage cock felt good in her teenqge pussy. Even when she was close to her fertile cycle, they had sex and she was amazed by the fact that she remained unfertilized back then. She never gave it much thought because thyey were both too oblivious of the risk on ince*st pregnancy. They just wanted to be teenagers who fucked each other for sexual pleasure.