I know some, although I should note that I haven't played all of these but I heard they all involve consensual sex in some way or another:
Dungeon of Erotic Master not RPGM, but I figured it's worth a try. The main characters are a bunch of sluts who go dungeon-crawling to fuck monsters. There's a dedicated ability just for seducing monsters and you get extra gold from the fight.
Breeding Season there's more scenes with the female main character than the male one, and all of them involve consensual sex with monsters cause that's the premise of the game. Some of the monsters are more human-like, some are more beast-like. It needs flash but there's a link to a standalone flash player in the thread, I believe. If not, you can run it using BlueMaxima's Project Flashpoint.
Breeders of the Nephelym basically 3D version of Breeding Season.
Slice of School has stuff involving insects.
Zombitch ~Slutty Gal's Holy Sex War~ been a long time since I played this one, I can't remember if sex is consensual or not but judging from the title, eh maybe?
Ghost Town Gunsweeper also been a long while since I played this one but I remember the main girl being a slut who wanted to fuck the ghosts and the game had a mechanic of fucking the enemies mid-fight.
Monster Tamer Aria
Treasure Hunter Claire
Karryn's Prison
Meltys Quest
Claire's Quest
Knight of Erin
Pokemon Ecchi Version
Creature Hunter