You already have it - you've had it since you were just a few cells in your mother's womb. It's your skin !
You get your birthday suit instantly when your born (skin) So your only in your birthday suit when your Naked. (shirt and all). (You got your skin on the day your born)
A birthday suit is what you were wearing when you were born - you are naked.
It's called your birthday suit because when you're born, you're born naked. Your "birthday suit" is your skin.
His Birthday Suit - 1930 was released on: USA: 9 March 1930
The cast of His Birthday Suit - 1930 includes: Cliff Bragdon Carl Herman
their birthday suit
Watch
nothing but their birthday suit
The Lazy Song by Bruno Mars says "I'll just strut in my birthday suit".
Because birthday suit means what you were like when you were born (naked) it does not actually mean an item of clothing.
His birthday suit
Nothing but her birthday suit!