2 girls 1 cup is a disgusting video, but also is an internet phenomenon which is to trick your friends into watching it. Videos of reactions to watching 2 girls 1 cup are famous online.
"-hey, have u seen this video called 2girls1cup ? you should check it out, its hilarious
-ok, ill google it tonite"
"-you motherfucker! that link you sent me was the nastiest shit ive ever seen
-oh, 2 girls 1 cup ? lol"