"Goo! What the hell is that?"
Y and X hug (in unison): GOOOOOOOOO!!!!!!
X: Surprise! Happy Birthday!!!
Y: GOOOO! awww, guys, you didn't!!!
Y blushes and smiles the biggest smile of all time
The actual goo may not sound like goo but is best sounded out as goo. Goo's loudness depends on how intense the moment is.
I kicked dads gun, thinking it was empty. The golden hollow point ricoche'd and blew his head off GOOOOOOOOOOOOOOOO!!!!!!!!