Someone who makes cow noises when they talk, frequently used as a comeback to an insult.
"You sir, are a strumpet"
"You Ma'am, are a Moo Mouth"
Wait what!? I can't you fucking idiot. There's a hole in my tooth!
Hym "You have got to be fucking shitting me, does NOT chewing with both sides of your mouth contribute to TMJ!? Well what in the fuck am I supposed to do about that now you son of a bitch!? God damnit. Oh and does my concern for the spontaneous increase in the severity of my symptoms insult you? Is it not worth your time? Fucking prick."
Bruh it’s shaped like a circle or two semi circles.
Taylor has a circle mouth it looks like 2 semi circles put together.
Someone with really messed up teeth
I was watching anchorman and realized that Will Ferrell has a gutter mouth.
When the sassy black nurse puts her hands on her hips, cocks her head to the side, raises her eyebrows, purses her lips, and says "mmmm-hmmm!", she is making a butthole mouth.
Trump's press secretary has reached out to actor Gary Coleman in hopes the former child star can help the President make a proper butthole mouth.
Sucking a dick after it has been in your or a butthole.
I was fucking this bitch in the butt, pulled my dick out and shoved it in her mouth before she knew what was going on and I laughed and called her Butthole Mouth.
A less rude and more playful way to tell someone to shut up
Person A: Did you know that-
Person B: Dude shut the hell your mouth with your family feud ass questions