Boy 2: (After he was given the insta-gasm) (yelling) IT'S SO INSTANT!
2) Noun: An act of instantaneously, and uncontrollably jizzing in one's pants as a result of the aforementioned reasons.
Girl 2: OMG yeah I know, my ex-boyfriend always used to tell me how she was such an instagasm (it's part of why we broke up, can't have my man chasing another woman).
Girl 1: What's an instagasm?
Girl 2: Look it up on urban dictionary, duh!