Nicky Nacky, a reference to Venice Preserved; or, a Plot Discovered (1682) by Thomas Otway. Although the play is a tragedy, it includes (III.i) an exchange between a foolish and randy Venitian senator, Antonio, and a prostitute named Aquilina. Antonio's pet name for his mistress is "Nicky Nacky." The dialogue’s tone might speak for itself:

Nacky, Nacky, Nacky — how does do Nacky? Hurry durry. I am come, little Nacky. Past eleven o'clock, a late hour, time in all conscience to go to bed, Nacky — Nacky did I say? Aye, Nacky, Aquilina, Naquilina, Naquilina, Acky, Acky, Nacky, Nacky, Queen Nacky. Come let's to bed, you fubbs, you pug you, you little puss — puree tuzzey — I am a senator.

You are a fool, I am sure.