I saw this episode in America and I was wondering what season it's from, I think the story is something like Cliff takes Rudy to a dancing lesson, the scene I remember is when Cliff is having a challenge with someone.

Episode 143 - Mr. Sandman:

http://www.tvtome.com/tvtome/servlet/GuidePageServlet/showid-481/epid-12883/

Thank You!