The guy in this video has a typical reaction: the "Oh my God!," the hand over the mouth, the turning away, the cursing, the inevitable looking back. Watch enough reactions, and you start to feel like a junior-league Guillame Duchenne, the 19^th-century French neurologist who studied human expression by stimulating the facial muscles with electricity. To watch 100 of these videos is also to gain a rough idea, based on the comments that people blurt out, of what actually happens in 2 Girls 1 Cup. (A complete exegesis is available on Wikipedia.) I won't spoil the surprise, except to cite a 1993 study that posited a "Disgust Scale" involving seven categories of disgust elicitors: food, animals, body products, sex, body envelope violations, death, and hygiene. According to my third-hand experience, 2 Girls 1 Cup is off the charts in body products and hygiene.