Fucking my brother in law without my sister knowing

His brother-in-law came to visit and rang the bell just as he finished getting out of the shower. it looked like the bastard had it all figured out. he was married to his sister and always bragged about being a macho, but what he really liked was breaking men's butts, especially his own brother-in-law, seeing him alone with a towel covering his body, it didn't take long to make him see that he had to take it off. he did so, and with his ass well placed he could not avoid the temptation to go and penetrate him. in fact it is actually what he had gone to look for. he penetrated it hard, he loved to feel his straight male cock fucking her ass, that's why he moaned like that until they finally came.