The Reverse Peephole (a.k.a. The Man Fur) Season 9, Episode 12

Jerry

Ow! Sharp key.

Kramer

So, you're sleeping with Silvio's wife?

Newman

Well, there's very little sleeping going on.

Kramer

Well, why didn't you tell me about this?

Newman

Quite frankly, I don't see how it's any of your business.