As told by my somewhat prudish sister:

It was Christmastime and the mail carrier was out delivering his sack of cards in a somewhat upscale neighborhood, had a few bottles of wine and spirits given by some of his clients. He arrived at one house with a door that had a slot for mail delivery. As he was about to slip a pile of cards into the slot the door swings open and there stood a very attractive, scantily clad woman who invited him in for lunch.

He accepted the invite for a free lunch but when he was finishing his meal the woman started massaging his shoulders and asked, "Want to go upstairs and fool around?"

Intrigued he accepted. So they had a fun romp in the sack which he thoroughly enjoyed but as he was getting dressed the woman handed him $10!

He asked what that was for and she replied,

"I asked my husband what to give the mailman for Christmas and he said, 'Fuck him, give him ten bucks', lunch was MY idea!"