Another language/culture barrier issue. In America, we might think that these are the kind of idiot young people who somehow think that simulating oral sex in a photograph makes them look funny or cool. But in France, this gesture actually refers to eating snails (
l'escargot), a national delicacy. These culturally gifted young men are simply saying that they look forward to an elegant 5-course meal at an unspecified later date. So don't judge.