A phrase used for a military person who wants to have relations with a person who could possibly be under age but the UCMJ says as long as she's 16 its fair game.

Also can be used to combat the phrase 16 will get you 20
#1

Sailor: Hey check out that girl over there she is fine as hell i would destroy her pussy

Marine: Dude she looks 16 years old

Sailor: Hey UCMJ says 16's OK

#2

Guy 1: 16 will get you 20

Guy 2: Yea but UCMJ says 16's OK
by Mr. Tiddlesworth June 6, 2010
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