Big Boy Pants 

A metaphor for taking responsibility for mature adult affairs such as finances and occupational obligations.

Put on your big boy pants and go pay the rent!

Big Boy Pants by letithappen88 November 8, 2017

Big Boy Pants 

Pants with features such as zips, buttons and belt-holding-apparatus on the waist. big boy pants often feature buttons that require certain finger strength and finesse to handle.

Unlike other more common pants, staining Big Boy Pants results in anger/frustration with ones parents. Known from Cult Classic action comedy thriller "The Other Guys"

"you wake up in the morning and shout: i put on my big boy pants?"

"look at Jimmy already wearing big boy pants"

Big Boy Pants by Not Timothy Dalton December 2, 2013