Big on and Rubbing it in

Today's material consists of two idioms: to big on something and rubbing it in.

The first idiom, big on, means 

Believing that something is good or important  

He's very big on jazz.  

She's not big on cooking.

This idiom probably has its origin in the phrase "to be a big fan ".

The second idiom, rubbing it in, means 

To emphasize one's strengths or another's weaknesses in a manner that degrades another. 

I know you're a better painter than I am, but you don't have to rub it in. 

With his team ahead in the ninth inning by five runs, the baseball manager decided to rub it in some more by having one of his slowest runners steal second.