spockblocked

indirectly (through the use of clever words or space/time paradoxes) stopping a friend from getting laid or finishing the sex, if he does get laid.

You: Dude, you should jerk it before she comes over tonight, just in case you get laid. She'll think you last longer!

*friend, later that night after jacking off: sex lasts so long parents interrupt, meaning he couldn't finish*
Friend: Damn, he totally spockblocked me!