I think that there is some really varying views on what Cockblocking is.

IMO...

Cockblocking is whenever someone swoops in and fucks up everything you were doing to hook up with a girl, be it for sex or just hanging out.

Guys can cockblock, and are the usual suspects, but women can do it to. But the woman you are trying to hook up with cant cockblock you, thats just being denied.

A cockblocker doesnt even have to steal the girl, a friend of family member can be a cockblocker, by saying something, or doing something to draw away from everything you were doing.

If anyone watches Scrubs, the episode with Elliot screwing over JD and his chances with the girl, where they do the little thing across the screen "Elliot somethingoranother, Moment Killer". Well, moment killing = cockblocking. You are blocking that mans cock from doing anything with that woman.

..yeah.