Feed for no more than 90 seconds of real-time contact. Then, excuse yourself. Leave while they are still confused —not satisfied. A confused target remembers nothing but a pleasant feeling. A satisfied target becomes obsessed, and obsession leaves traces.
In scenes involving your identity as an incubus, choosing to prioritize the mission often yields long-term benefits over instant gratification. Mid Game (v0.8a) stray incubus guide
If you can tell me or which version of the game you are currently playing, I can give you a more specific walkthrough for those scenarios. Feed for no more than 90 seconds of real-time contact