Isn't "Mister" the male equivalent of Mistress? 🙂
Or is it "sugar daddy"?. 🤔
Or maybe, Simp? 😂
I'm not sure, but is it not master? The example that pops to mind is K-9 (Doctor Who) when talking to a male char, he refers to them as Master, and a female as Mistress. They've also done it with the Master, when they changed gender, she became missy (Mistress)