Friendship between women.-
One night, a woman didn´t go to sleep to her house.
The next day, she said her husband that she had slept in the house of one friend of her.
The man phoned the 10 better friends of her wife.
No one of them knew nothing about it.
Friendship between men.-
One night, a man didn´t go to sleep to his house.
The following day he said his wife that he had slept in the house of one friend of him.
His wife phoned the 10 better friends of his husband: 8 confirmed that he slept in their house and 2 assured that he even found there.