Tom: Hey, I heard the Rams lost to the Patriots in the Superbowl. Aren't you a Rams fan?
John: Yeah, yeah, yeah. You don't need to rub it in.
Sara: I heard you got another speeding ticket yesterday. You got one last month too, right?
Jill: Yes, and my husband's going to freak out when he finds out about this one.
Sara: Maybe you should start taking the bus to work just to be safe.
Jill: Thanks for rubbing it in.
Meaning: "to rub it in" is a common expression used when someone teases or reminds another person about something that is negative or embarrassing.