A man and a woman who had never met before, but who were both married to other people, found themselves assigned to the same sleeping room on a trans-continental train.
Though initially embarrassed and uneasy over sharing a room, they were both very tired and fell asleep quickly, he in the upper berth and she in the lower.
At 1am, the man leaned down and gently woke the woman saying "Ma'am, I'm sorry to bother you, but would you be willing to reach into the 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 replied "Get your own ****ing blanket".
After a moment of silence... he farted.