"It" is referring to showing your male genitalia to a certain lady (or guy if that's what your into).

This is the common reply you give to your friend when he continues to complain whether a certain girl is into him or not.

It's the ultimate test. If the girl doesn't take bait or if she's about to charge you for harassment, proceed to walk out the door and move on.
Pete: Hey Billy, Sara gave me a wink yesterday, but sometimes she doesn't seem interested in me.
Billy: Bro, when in doubt, whip it out!
by Notorious NATE October 12, 2010
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Common slang umong military enlisted to salute an approaching person in uniform when uncertain of their rank. Better to be safe than sorry. More common with the NAVY as Chief Petty Officers have gold anchors on their collars and are often mistaken for gold oak leafs (signifying a Lieutenant Commander or Major).
Bill- "Don't look now, but here comes an officer"
Larry-"No, it looks like a Chief Petty Officer from here"
Bill-"When in doubt, whip it out. Better to be on the safe side then to ignore him if he was an officer".
Larry-"You're right"

*Both saluting-"Good morning sir".
by awj_woody May 1, 2007
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