Sour nugget

A total bitch

A bitchy person

A cranky, mean Girl/Boy

An unkind person or an unreasonable person

Figure1- Hey, wanna come to my party?
Figure2- No! Your parties are always horrible!
Figure3- Stop being such a sour nugget!

Girl1- I love your top!
Girl2- I love it too! Your's is okay.
Girl1- Whatever, sour nugget.