How does Bryon manage to enter the bar/pool hall even though he's underage?

Bryon manages to enter the bar/pool hall even though he's underage because he is friends with Charlie, the owner and bartender. Bryon explains that he used to like Charlie's younger sister. Bryon became friends with Charlie while he was dating his sister, and remained friends with him even after they broke up. Bryon says that it's unusual for this to happen, but useful so that he can hustle pool games.