HAUGUGUGUGU

An appropriate reaction to seeing someone's exceptionally big behind and/or thighs.
Equally appropriate when, if visibly seeing such, watching someone twerk.

Friend A: "Yo bro, do you see that girl over there? look at that cake she packing!"
User: "Oh for real? it can't be that bi- HAUGUGUGUGUGU, what the hell, that ain't cake, that's a whole damn bakery!"