Friends of Women:
A wife was not at home for a whole night. So she tells her husband, the very next morning, that she stayed at her (girl) friend's apartment overnight. So the husband calls 10 of her best (girl) friends and none of them confirm that she was with them.

Friends of Men:
A husband was not at home for a whole night. So he tells his wife the very next morning, that he stayed at his friend's apartment over night. So the wife calls 10 of his best friends and 5 of them confirm that he stayed at their apartments that night and another 5 are claiming that he is still with them!!