When you need to hide an erection and you tuck it straight up into your waistband/beltline. The cock is similar to the hand of a clock at the 12-o-clock position.
guy: Hey, can you tell I have a raging hard on right now?

girl: What the fuck?

guy: Yeah, just did a little 12-o-clock tuck.
by rza00036 September 20, 2007
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When you get a boner in public and flip your cock up into your waistband.(It feels good so try not to bust a load into your bellybutton.
"Dude I was in class and I was thinking about Gabby Bedard and Brandon Smith cuz I'm bi, and I got a boner so I did the 12 O' Clock Tuck. Works everytime. No one knew I had a boner. Except I did bust a load into my bellybutton cuz it felt good." said Tucker Kreis
by Brandoner Smith December 31, 2008
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When your in public and you get a boner, so you flip your cock up into your waistband. It feels really good so try not to bust a nut into your bellybutton.
"I was sitting in class thinking about Gabby and Brandon, cuz i'm bi,when I got a boner so I did the 12 O' Clock Tuck and no one knew I had a boner. It felt so good, I almost busted a load into my bellybutton." said Tucker
by Brandoner Smith January 2, 2008
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