Drink Thought Exclamation

A "eureka" moment but instead of exclaiming "eureka," you exclaim "mmm" because your mouth is full of water.

Two entrepreneurs (E) drinking:
E1: "We need a business idea."
E2: "Yeah, but what?"
E1: *Takes a drink and comes up with an idea* "Mmm!"
E2: "I know that sound! That's a drink thought exclamation!"