A mix of seduction and domination in a lesbian game. Ideally a dominant lesbian seducing a milf who was straight before. I know, the scenario is quite unrealistic, since you can't change a person's sexual orientation, no matter how good your seduction skills are, but maybe it's that impossibility, that makes the scenario so hot for me. This may well count as corruption too, if the character to be seduced is cheating on her husband in the process.
Romance IMHO is something for real life and for regular games, but not necessarily for porn games.
Blackmail may be a starting point for a domination game, but a rather weak one, as it suggests that the MC has to rely on dirty tricks to get women into bed.
Mind control is a rather lame excuse. While I like supernatural and sci-fi settings, mind control makes all the action kind of weaker, as one character is not genuinely into the other, which weakens the tension. So, if a scenario is unlikely enough that it requires some sort of force (such as a son trying to dominate his mother), I'd still rather create a blackmail scenario than a mind control one.