how about mister?
Although I like the straightforward direction of using "mister" for this, I have residual gut-twinge. "Mister" is derived from "Master" or "Meister" and indicates the one in a position of authority while the feminine form "Mistress" would normally indicate the chief female authority in the house. I think we are going to have to avoid any derivative word from northern Europe if we don't want to carry in some diminutive. Everything would come out like 'boy-toy' or 'pool boy'.
Or we can always result to more direct route and say "Lover"
p.s.-Happy Valentine's Day.
along your lines...i was listening to Stevie Wonder's "part-time lover".
Martha's link to Catullus...apparently, he had an affair (woman referenced in the posted poem) with a married woman. so, Catullus could be an option.
there is the word, "jump-off" -- its been in the hip-hop community for quite some time. it references "the lover" that you have on the side. the call is only made to that person when you want things to jump off.
Ok, I can deal with Catullus (although I think most people would think catalyst), but if you are gonna pull out 'part-time lover' and 'jump-off', we might as well go for 'the slice on the side'. lol
In response to the question of a name for the lover of a married woman in the Valentine's Day episode, there is an Italian word called "cicisbeo". He was the professed gallant and lover of a married woman, who attended her at public entertainments, to church and other occasions and had privileged access to his mistress. Although the origin is unknown it may have come from a translation of "in a whisper" or an inversion of bel cece which means "beautiful chick (pea)". There is a similar word in Spanish (cortejo or estrecho) and in French petit-maître, but I think the Italian may be closer to the intention of the caller. The exact etymology of the "cicisbeo" is unknown; some evidence suggests it originally meant "in a whisper" or an inversion of bel cece, which means "beautiful chick (pea)".