It's wrong to talk in class and disrupt the class.
Dean has just received some excited and good news while he's sitting next to his friend in class.
Dean wants to share the news with his friend.
Dean waits until after class is over to share the news with his friend.
Dean tells his friend what happened while in the middle of class.
The class is productive and everyone learns the new material effectively.
The class ends up getting interrupted by Dean talking to his friend.