look up any word, like darude - sandstorm:
 
1.
An insult in which you tell someone to brush their teeth while making a masturbation gesture toward your mouth, simulating oral sex and teeth brushing at once.
Bill:Hey Bob, you're a total dick

Bob:Yea, well why don't you go (simulates filatio) brush your teeth
by Hitman 2-1 September 02, 2008
 
2.
To give a blow job and let someone come in your mouth.
I helped you brush your teeth!
by Anon234 September 13, 2006