Green’s Dictionary of Slang

wedding n.

[? SE weeding]

the emptying of a privy.

[UK]Grose Classical Dict. of the Vulgar Tongue n.p.: Wedding, the emptying of a necessary-house in and about London.
[UK]Lex. Balatronicum [as cit. 1785].
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.

In compounds

wedding night (n.)

(Polari) the first sexuak encounter between a gay couple.

[UK]P. Baker Fabulosa 299/1: wedding night the first time two men have sex together.