Just because freshly single Nick Cannon spends a night with smoking hot (and freshly single) Amber Rose at an amusement park … does NOT mean they’re banging — it just looks like it. But Nick broke it down for us last night on his way out of a sushi joint in the Valley — explaining why the video TMZ got of Amber and Nick on a roller coaster Friday night … is proof they’re absolutely nothing more than friends. He makes a solid point … unless he’s using reverse psychology.