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