Karma Kramer?

I wonder too myself. Must have something to do with one of the ingredients found in butter to get that smooth feeling.

Ok, here's the full scene as it happened:

Kramer: Did you see Bania's set last night? 'Cause I read on the Internet he killed.

Jerry: He killed. He only does well when he has me for a lead-in. He's a time slot hit.

Kramer: Well, you gotta give him some credit. (starts rubbing a stick of Jerry's butter across his face) You're just being totally ridiculous. (keeps rubbing) I'll see you later buddy.

Jerry: Wait, wait, wait, wait, wait a minute.

Kramer: What?

Jerry: Do I have to ask?

Kramer: I ran out of butter so I had to borrow yours. Anything else, Mr. Nosy?

Kramer starts to walk out, Jerry grabs him by the shirttail and drags him back.

Jerry: Why are you buttering your face?

Kramer: I'm shaving with it.

Jerry: Oh Moses smell the roses.

Kramer: Jerry, it's vastly superior to any commercial shaving cream. Now feel my face.

Jerry: No.

Kramer: Feel it.

Jerry: I don't want to.

Kramer: Feel it. Feel it.

Jerry (places two slices of bread against Kramer's face): That is close.

Kramer takes the bread and eats it as he walks out of Jerry's apartment.