A boy who you are making out with, who approaches the state of boyfriend - without ever reaching it.
"My asymptotic boyfriend Matt continued to introduce me as his friend whenever we ran into people he knew while we were out, despite having been dating for a couple of months."
The school of thought in which a movie may approach the level of Braveheart, but may never reach it, only head towards the theoretical infinity where Braveheart resides.
It should be noted that the x-axis on which the Braveheart Asymptote exists does not necessarily refer to a single idea (i.e. quality, awesomeness, number of bagpipes) but rather everything that Braveheart is and all other movies aspire to be.
Dude 1: Independance Day was a fantastic movie, maybe better than Braveheart.
Dude 2: Unfortuntaly, that is impossible
Dude 1: Why's that?
Dude 2: Because of the Braveheart Asymptote.
Dude 1: Oh, yeah, ok I get it.
1/Dating; a relationship where you get progressively closer to dating but never actually reach dating. Not to be confused with pre-dating, asymptote dating never leads to actual dating.
Ugh! Why won't Alex and Jon get together??? They're totally asymptote dating.