I don't have many suggestions, but NPC reactions to player choices sound like a great idea. I don't know, maybe some NPCs recognizing the player after you've worked in the Tarkas Bar a certain amount of times? Groping dialogues based on how much you've "gotten around"?
In some RPGMaker lewd games I've played, there would be instances where you'd walk past certain npcs and be catcalled, groped, or recognized from past public ventures. By "groping dialogues", I meant you'd get accosted by a random pedestrian, but there was not artwork or a major lewd event tied to it. So it was basically just flavor text.