Bugs (2003)

Other mistake: Garcia, in a manic moment, dips his right fingers into the bug's acidic saliva, then stripes his left cheek, where the acid eats into the flesh. A couple of minutes later, he dips the same two fingers back into the substance, and proceeds to stripe his right cheek, where the acid immediately starts eating through his skin. Oddly enough, the fingers aren't affected at all, despite being dipped into the goo twice.