Wedding Night Sleepwear

wedding night
The night after a wedding (esp. with reference to its consummation)
the night after the wedding when bride and groom sleep together
A wedding is the ceremony in which two people are united in marriage or a similar institution. Wedding traditions and customs vary greatly between cultures, ethnic groups, religions, countries, and social classes.
Wedding Night (French: Nuit de noces) is a 2001 Canadian comedy film.

sleepwear
Pajamas or other clothing suitable for wearing in bed
nightwear: garments designed to be worn in bed