Eh, if I think too much about it, I'll end up renaming the game to "A game with lots of missed puns. Also there's NTR".I'm surprised you didn't use 'I'm dreaming of a white Christmas' song while the husband asleep and Santa giving the wife and daughter some milk and cookies of his own. makes it a whole double meaning what with all the new decoration Santa has been making around the house!
Sorry but all I can think of are puns...
I'd love to get into the genre myself to be honest, I do have RPGmaker MV fully from steam but I'm wondering if the sex sprite sheets are stored somewhere or I'd have to use pixel art to draw them myself.
P.S. I also agree with the slow steak analogy, hate games where it is too 'in your face' and goes from 0 to 100. I like the sneaky element of it.
As for RPG Maker, Vx Ace has a database with some pre-made sprite sex animation spritesheets, but the one for MV is quite poor I'm afraid. Which is why I got into Vx Ace first, so I could use some of those animations and do some myself (the sprites for Vx Ace being smaller, they require less details so it's easier for beginner to draw themselves). I'll make a game in MV in the future, but I'll ask a pro pixel artist to make them then. I could still link the database page to you if you want(all in Japanese tho).