^5!!! Ya done good, Junior!
... but you better watch out, you do that to her too much she's gonna fall in love with ya!
Okay, there really is both a scientific and metaphysical reason why this happens. The scientific is that in a really powerful orgasm the brain gets flooded with tons of endorphins and that sort of short circuits the emotion wiring. Its the same thing as when people who are really happy burst into tears.
Metaphysically ... ah, never mind
Put it this way, it's what tantra is all about, I'll leave it there.