Friendship among women
One night the wife did not come home. The husband asked her where she had been and she said sleeping over at one of her girlfriends. The husband calls ten of her best girlfriends, but none of them did confirm.
Friendship among men
One night the husband did not come home. The wife asked him where he had been and he said sleeping over at one of his friends. The wife calls ten of his best friends, eight confirmed he stayed over and two said he is still there.