Unless
the boobs are non-existent, and the nipples resemble something that looks like two thumbs glued to a ironing board.

There's a divine ratio to consider here - the erect nipples must be proportional to the size of the boob, otherwise it's a total hard-on killer.
(god_is_a_ghoti Carpe Deum., Wed 12 May 2010, 14:01, Reply)