I'll be Upstairs! - A lie you tell when you're about to do something that’s gonn

A lie you tell when you're about to do something that’s gonna make you look like a fool.

I'll be upstairs! (He came back with a new nickname: 'The Pizza King.')

I'll be upstairs! (He came back with a new hobby: yelling at the ceiling.)

I'll be upstairs! (He came back with a new job: 'Professional Pizza Eater.')