I dunno about one word or a few words...I think the whole sentence just needs to be erased. Unless he's describing an unusual situation where's he's rockin the toothbrush in his mouth.
"Man I'm on stage rhyming...toothbrush all in my mouth."
Out of place...but I could hang with that.
But, "I'm brushing my teeth...toothbrush all in my mouth." That's real redundant. Use that space to describe something else fool!

I'd be "all", but I'd agree with the Yohance.

Filed under "good for you"? Or "what the fuck are you talking about"?

-IV

Tootbrush is a metaphor for cock---LIKE DUH!

maybe he just means the entire toothbrush is in his mouth. His gag reflex is long gone, obvs

Oral Hygiene is very important I for one salute Mr. Median. He's not going to get any cavities all up in his mouth thats for sure.
http://tsanda.wordpress.com/

hahaha. why not say "razor all on my face" and "deodorant all in my arm-pit" and "shoes all on my feet".

how BASIC

The full line is "Toothbrush all in my mouth, she tryin to get the story" because he is personifing the toothbrush as a curious woman, and the expression "all in my mouth/grill" is commonly used for nosy people. throughout the song he personifies every thing in a regular day.

though at face the line does sound odd. Why isn't MF DOOM on this site yet?