Sidestepping in mild interested-like-a-vulture-seeing-an-interesting-carcass-mode the confrontation with drunken jealousy inspired, I can agree with the whole, “Unavailable is apparently an aphrodisiac” thing.
There are people who seem to think that saying, “No, sorry. I am taken.” is an invitation to try harder.
Sometimes it is cute. Sometimes it is creepy. Sometimes it is damned scary.