gainax bounce - The wild, over-the-top movement of fake boobs in anime. It's

The wild, over-the-top movement of fake boobs in anime. It's like they're bouncing to their own beat.

'I can't focus on the story. All I see is her boobs doing the cha-cha.'

'That gainax bounce is so intense, I think the character is gonna get a hernia.'

'Her boobs bounce harder than my mom's vacuum cleaner.'