Quote Originally Posted by nk_8950 View Post

Laughter is caused by endorphins produced by a stimulation in a certain part of your brain after something usually profound or exciting. By enduring the flogging, something that you love, it would probably provoke those endorphins being produced.
This hasn't happened to me (yet ) but from what I've read, nk_8950 explained it well. There's a quote in The Bottoming Book: "many bottoms go down with a scream and come up giggling" that I hope to find out from personal experience describes it perfectly.