What a good introduction to the girlfriend's parents. Although the stepmother is not her own mother. Still, she also decided to do her part in raising her stepson. The method she chose, it is true, is not the most popular - I have sex education. But I think it's a pretty brave decision. Considering that she is not his own mother, it cannot be considered incest; on the other hand, for this lady's husband, it cannot be called treason. Since it is his own son. Everybody wins!
It's like a harem - you come, you fuck all the chicks, and you feel like a sultan! I'll take my wife to swingers - as an entry fee to the club of sultans! )