A man and a woman who had never met before find themselves in the same sleeping carriage of a train.
After the initial embarrassment they both go to sleep, the man on the top bunk, the woman on the lower.

In the middle of the night the man leans over, wakes the woman and says, "I'm sorry to bother you,
but I'm awfully cold and was wondering if you could possibly get me another blanket?"

The woman leans out and, with a glint in her eye says "I have a better idea, just for tonight,
let's pretend that we're married!"

The man says happily, "Sure. That sounds great!"

The woman says, "Good... get your own fucking blanket!"