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They say this town (Hollywood) is really so small, but who woulda ever made a connection between Mary-Kate Olsen and Spencer Pratt!

MK told David Letterman last night that the two went to high school together, where Spencer often threw a tantrum on the soccer field, walking out on several games.

But when Dave expressed shock that the guy would even break a sweat (cuz no one's surprised that guy has temper tantrums), MK said "oh my God, that brings up stories!"

EW.

She thankfully declined to elaborate on the topic.