When I wrote "pimp out" I meant it more in a "getting them to have sex with strangers" way, though proper pimping does show up occasionally. I'd say the two incest sharing games worth playing the most are Love & Vice and Starmaker Story. They both already have a large amount of content and I trust both of their developers to actually finish their game. I'm not even a fan of "real porn" HTML games, but Love & Vice is so great I can ignore that complaint. And thankfully the dev is making a new game with 3d renders called Sins of Night which is also extremely promising, though it's still very early.
For family fuckfests the two other games worth checking out are Family Vacation and Golden Mean (I think this one also has an actual mom pimping side plot, though its tone wasn't to my taste). Outside of that, if you want incest sharing you either have 1) smaller scenes in good games that otherwise aren't focused on the kink (like Desert Stalker) and/or that might get more stuff in that vein eventually (like Photo Hunt), or 2) do some digging for specific game tags and maybe lower your standards.
Some specific examples I can think of for whatever reason: Dating my Daughter (Maybe unfair that I forgot to mention it above, I was thinking more of currently active games. It's actually complete, though the swinging/sharing is just an optional branch. Also check out the "Fantasy Scene Collection"), Take Over (and the much less developed Cross Worlds), Total Seduction 2 (and basically most of his other games), My Best Deal (just one small scene for now), Roundscape Adorevia (Again part of a larger game with LOTS of kinks. Pick Farmer start, you can also search its name in this thread as I went into much more detail about it in a post).
I've also just realized that I've only posted male MC games. Female MC games in the genre do exist, though there are even less of them and this post is long enough already
