Similar to a bathroom buddy. It's when two or more girls who regularly go to the bathroom together when out in a public place, also seem to be online at the same time on facebook.
"Amanda and Christie went to the bathroom together at the bar the other night and I always seem to see them on at the same time on facebook."
"So they're each others facebook buddy?"
"Bingo."
"So they're each others facebook buddy?"
"Bingo."
by Flirbertz (M.Richie) November 12, 2009