Green’s Dictionary of Slang

mutter and stutter n.

butter.

1960		J. Franklyn Dict. of Rhy. Sl.
2002		D. Shaw ‘Dead Beard’ at www.asstr.org 🌐 I tell her I could use some mutter and stutter to lubricate things up, so Monica comes to the party with a tube of suncream she has with her.