wedding night       
noun [ C usually singular  ] uk/ˈwed.ɪŋ ˌnaɪt/ us/ˈwed.ɪŋ ˌnaɪt/
 新婚之夜
the night of someone's wedding
  They spent their wedding night in a local hotel. 他们在当地的一家酒店度过了新婚之夜。 
 The story describes a pair of newlyweds on their wedding night, struggling to communicate and understand each other. 故事描述了一对新婚夫妇在新婚之夜难以与对方沟通和互相理解。 
 - More examples
 - They booked a suite in an expensive hotel for their wedding night.
 - They dated for five years, but they didn't sleep together until their wedding night.
 - The couple came ashore after apparently spending their wedding night aboard the yacht.