Undershirt

A vest or undershirt (US) is an article of underwear worn underneath a dress shirt. This Shirt worn by the older generation or a person called Brendon. The Brendon type undershirt wearer also tends to repeatedly sing 'somewhere out there' and sleeps on a deflating blow up mattress.

Lexi: Hey! Mr B why are you wearing an undershirt??

Mr B: Because i'm going to be 30 next year!