Juan, two, three

First hear of in Proof (movie):

Paste-eater: Another term for a geek, nerd, dweeb. Someone who does not fit in. Refers to the kind of kid who got in trouble for eating paste in preschool activities. I.e.: Watching Star Trek reruns is for paste-eaters. [ source ]

P.S: Paste is not related to ‘pasta’  as it could resemble “gafa-pastoso”