When you are playing a board game and you have to reach far across the table to draw a card or move your piece, the player chops their boob into the edge of the table creating an undesirable effect.
a nipple that seldom remains concealed by a bra, or any article of clothing, meant to conceal it - usualy occures when an areola is significantly larger than that of the average nipple
"I love when chicks with silver-dollar nipples wear scoop-neck tops... every time they move, there's a PEEK-A-BOOB!"