in your birthday suit

US /ɪn jʊər ˈbɜrθ.deɪ suːt/
UK /ɪn jʊər ˈbɜrθ.deɪ suːt/
"in your birthday suit" picture
1.

nu, em trajes de Adão

naked; without any clothes on

:
He was caught running around the garden in his birthday suit.
Ele foi pego correndo pelo jardim nu.
She felt embarrassed to be seen in her birthday suit.
Ela se sentiu envergonhada de ser vista nua.