When a male and female are out of protection and birth control and the guy wants to piss in her to feel the satisfaction of release and not get her knocked up.
Man 1: Dude i need some protection, help me out.
Man 2: Nah dude i'm out, you should just piss-jaculate in the girl.
For individuals it is when someone shows their appreciation Facebook post by BOTH using the thumbs up function as well as mentioning how much they like the post in a comment.
Alternatively, it refers to excessive "likes" by many people on the same post (approx 10 or more).
Tegan's FB Post: @thedaleks when will you learn? (updated via Twitter)