[sent to me by someone not wanting credit, making the rounds - ed.]
A man and a woman who had never met before found themselves assigned to the same sleeping room on a trans-continental train. They tried to make other arrangements, but the train was full and they were both very tired. They agreed to make the best of it for at least one night. There were two berths, and the man gallantly agreed to take the upper one.
At 1:00 AM, the man leaned down and gently woke the woman saying, "Ma'am, I'm sorry to bother you, but would you please reach into that closet to get me a second blanket? I'm awfully cold."
"I have a better idea," she replied. "Just for tonight, let's pretend that we're married."
"Wow! That's a great idea!" he exclaimed.
"Good," she said. "Get your own fucking blanket."