The husband of a lady with pink hair is stormy from anal sex with his wife

A lady with pink hair has been married for several years and knows very well what her legal spouse likes. Having aroused a member of the man, she sits on him with an anal hole and the guy gets such a wild pleasure that he cannot restrain himself for a long time and endures violently. I wonder why a couple to invite the third for a gangbang, since they have already mastered anal sex?