Aerosmith’s Walk this Way (1975) contained the line “you ain’t seen nothin’ till your down on the muffin”, which i’d venture to guess was Lady Gaga’s source for the slang term.

I couldn’t verify online, though i seem to remember reading an interview with Steven Tyler in the late 80’s in which he was asked about Tipper Gore’s commendation of Walk this Way as an example of wholesome rock and roll lyrics, to which Tyler replied, “she obviously doesn’t know what a muffin is.”

The lyrics in Rock n Roll have always had more then one meaning “Cause you know sometimes words haveTwo meanings” ( Taken from the song: “Stairway to Heaven” a song by the British rock band Led Zeppelin, released in late 1971. It was composed by guitarist Jimmy Page and vocalist Robert Plant for the band’s untitled fourth studio album and usually referred to as Led Zeppelin IV).

My interpretation to Lady Gagas “Poker Face”, (released September 23, 2008) phrase ”Bluffin with my muffin” is that bluffing is lying, or faking interest, or enjoyment to talk with, or be intimate with a person. Gaga more specifically means bluffing with her female sexuality to get intimate and eventually (fake) orgasm with the person she is targeting to get what she wants.  Muffin, being her female sexuality, specifically vagina being the lure to getting money, social status or something else.

Other meanings according to Wikpedia, (http://en.wikipedia.org/wiki/Poker_Face_(Lady_Gaga_song) sugggest “The main idea behind the song is bisexuality and was a tribute by Gaga to her rock n’ roll boyfriends. Lyrically, “Poker Face” is about sex and gambling”.

I don’t care, it’s a good work out song.