When a girl gives a guy a blow job repeatedly and the guy eats her out. It must all happen in the same night and the guy must be older. Usually done when sex is wanted but impossible due to lack of a condom.
Friend 1: Hey did you and Sally go all the way last night?
Friend 2: Nah, we wanted to but didn't have protection, so instead we santangeloed.
A synonmym for platonic: indeed I feel it is a superior word to platonic, especially in the context of human male-female relationships. This is based on my personal experience of dating many girls but not having any sex. As such, I used to describe these relationships to my guy friends as being purely platonic when in fact my intention was not always that, especially if the chick was bang-worthy. But now I feel Plato himself must have had more sexual action with women than I have that it is more appropriate to describe a word using my name rather than the great Plato. Hence the word santonic - to describe a non-sexual, philosophical, academic relationship between a male and a female. It can also be extended to same-sex relationship if the user so desires.
John: Man, I have been dating Mary for 5 years and I did not get any pussy yet.
Jack: Whoa dude, that is one santonic relationship.