I have been seeing stuff on YouTube talking about two girls and one cup. I had no earthly idea what it was. Thankfully this video isn't on YouTube, as I'm scared I'd be scarred for life, like this guy:
OK it seems that Tubgirl just got outgrossed!* So for the love of God, stay away from 2Girls1Cup!
*I've never seen Tubgirl, but the descriptions of it are horrible.