ham it up

To act in an exaggerated way, typically in order to be funny. Your daughter loves to ham it up for the camera—you might have a little actress on your hands! This is a serious play, so please don't ham it up out there. My toddlers always seem to ham it up whenever we have company over.

ham up

To exaggerate a performance or act in an overstated or over-the-top manner, often to the level of being irksome or inappropriate. A noun or pronoun can be used between "ham" and "up." This is a serious play, so please don't ham up your part. My toddlers like to ham it up whenever we have company. With the way your daughter hams it up, you might have a future actress on your hands.

ˌham it ˈup

(informal) (especially of actors) when people ham it up, they deliberately exaggerate their emotions or movements: When we realized we were being filmed, we all started behaving differently, hamming it up for the cameras.

A ham is an informal word for an actor who performs badly, especially by exaggerating emotions.