In Superbad, Seth has no problem completely ruining the gym class soccer game to talk to his buddy. People seem a little annoyed, but not to the point of anyone kicking him out. The PE teacher barely manages an irritated "Come on."
Once you notice this, you'll see it everywhere. In Juno, about 30 seconds into the movie, everyone's favorite quirky preggo hipster interrupts a track team's cross-country practice to talk to her baby daddy, and the rest of the team continues as if nothing matters. Sandy in Grease tries the same thing, and can't seem to understand why Danny won't talk to her, despite the fact that he's obviously in the middle of track practice.