There's a really old Israeli joke, that tells the story of a little ant that wanted to cross a big gushing river. She came close to the river and saw an elephant in the water. She told him: "Hey elephant! can you help me cross the river?" So the elephant took the little ant on his back and brought her to the other side of the river safely.
The ant got off his back and said: "Thank you, Elephant!"
and the elephant said: "What do you mean 'thank you', get naked!'
The shocked ant got naked and the elephant of course, had sex with her.
Two weeks lated another ant comes close to the same river, realizes she can't cross the river, and noticed the elephant. "Hey elephant! Can you help me cross the river?" and the elephant took the little ant on his back and brought her to the other side.
The ant told him: "Thank you!"
The elephant said: "you're welcome!"
The ant insisted... "no really, thank you so much!"
and the elephant said: "you're very welcome!"
The ant walked away and mumbled to herself "gramma and her fairy-tales!"
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The reason I am telling you this joke, is because the line: "What do you mean 'thank you', get naked!' has become such a slang/ expression/ something everybody says ESPECIALLY when a hot chick says thank you.
so back to my original post:
What do you mean 'thanks' get naked