I own exactly one shot glass and it's never been used for anything else... Guess I've always been a stickler for quality control.
One thing I want to do when I find a new girlfriend and we become intimate is cum on her chest and then lick it off. That sounds hot.
For whatever reason, many women seem really turned on by the idea of guys eating their own cum or other guys' cum. Maybe this runs along the same lines as many men's enjoyment of lesbian porn.