The extreme salivation that usually sets in as a precursor to vomiting. Normally occurs during an extreme night of drinking, such as after a harsh shot or one beer bong too many.
I'd had like 13 beers, and I was doin fine. Then, Joe brought me the shot of Jack. As soon as I downed it, the Fountain Mouth kicked in, and I knew I was done. Next stop; Puke City.
by MikeyMxCx August 14, 2009
When a girl is deepthroating her partner and projectile vomits as a result of her partner's ejaculation.
"This girl was giving me head and puked all over when I came in her throat"
"You just got mouth fountained motherfucker!"
"You just got mouth fountained motherfucker!"
by ShaggyTheBear September 29, 2017