Do orgasmic births really exist and, if so, how?

I recently found a disturbing (to me) collection of stories from real moms who claim they had an “orgasmic birth”. They claimed that they actually had an orgasm when they gave birth, making such statements as “He ricocheted off of my g-spot, and it made me cum so hard” and “It’s like having sex inside out”.

I, as a mother, can say that although my labor was relatively short in term of labors (5–6 hours), the physical feelings inside of me were nothing short of torture. It felt like the skin of my vagina was being torn apart, because it was.

So, what are your thoughts on this? Have you or someone you know had an “orgasmic birth”? How is it even possible, with all of the pain (or numbness from an epidural)?