Noun(1);A martini made with shit instead of Vodka. Made popular by the skanks in the 'two girls one cup' video.
Noun(2);being forced to admit failure despite trying your best is known as having to 'drink a shit martini'.
(1)Lesbian A:That 'two girls one cup' video was so fucking hot. Let's mix us up a nice shit martini.
Lesbian B:I likee, I likee
(2)Man A:I really tried all year to get that promotion, I even let the boss skull fuck me, but I still didn't get it.
Man:Yeah well, enjoy your shit martini you fucking furfag!