Making out with someone while you have a runny nose; and the unfortunate result of snot running down, often mixing in with the spit swapping.
Somewhat gross, but shows you really care about your wo/man; either that or you aren't picky and really just want to get some.
I have a cold, but still want to make out with my hottie! Totally going to give 'em a snotty sanchez!! haha!