nln0 gave some great answers. Here's a few more:
Solvalley School: Pretty much sex immediately and frequently, every action amounts to the characters jumping your bones, not to mention there is a lot of content (and probably the most girls I have seen in a game). I have heard
House Arrest by the same creator is the same way, but I haven't played it yet, so can't confirm.
Battle of the Bulges: Honestly, everything by Epiclust is solely about sex, though if hyper cock, hyper muscle, hyper breasts, well, just general size play, is not your thing, just skip his games. If those are not deal breakers, Battle of the Bulges has a sex scene available in the first minute, but also the gallery of every sex/nudity scene is unlocked from the started and can be accessed by pressing "C". His other games
Apocalypse, which is still in progress, and
Morning Lust are also in hypersexual worlds, though Morning Lust is a quick game (with a lot of clicking)
WVM: Plays more like a visual novel, but the game is harem focused still with the premise being, well, fucking people, and it doesn't take long to get a few girls under your belt. There is also a shemale love interest (well, two), but if that is not your thing, you can turn it off.
Terminal Desires: If you don't mind RPGM, Terminal Desires is pretty much just a bunch of horny zombies that you as the female protagonist can decide how slutty you are (a sex scene comes in the first 5 minutes). The game also features exaggerated bimbo features, which I know is a turn off for some. There are turn-based combat but you can surrender each battle (which results in a sex scene)
Nothing Can Stop Me Now: Like above, it's RPGM, but the story is essentially nonexistent, as the developer wanted the game to be 99% fucking to 1% story, and unlike Terminal Desires, there is no combat. Fair warning, English is not the first language of the developer and it definitely shows, but they are trying their best and has tried to look for editors but can't afford it.
The Doll House: I haven't played much of it, but I remember getting a sex scene pretty much instantly. The game is heavy on bimbofication, as is the creator's other project
Doll City.
Crimson Keep: You play as a half-incubus that gains power through fucking. There is turn-based combat but everything results in sex. Currently 5 chapters.
Tales of Androgyny: If you don't mind playing a trap in a hypersexual world of futas, this game is pretty much a ton of sexual situations and the turn-based combat is sex focused. It's also pretty Rogue-Like so pulling up a game has a different order of events.
Harem Hotel: I was thinking about not including this because I don't remember how long it took for the sex scenes, and there is a strong story and a lot of lore, but with a ton of content, a lot of options with the sexual actions including clothing, and of course once you run through it, you can keep grinding sex options. Wouldn't be my first recommendation, but it's a great game.
Fuckerman: Honestly, just a fetch quest point and click adventure, but each game is quick to run through and sex scenes come with just finding one item per person, so might as well include it.
