@Omanot Recorder of Eternity I kinda have this thought:
Imagine that the way succubus magic work is that it makes the person affected act exactly like they would if they were truly completely in love with you. And that it 100% worked on him... and he ended up just treating her the exact same way as he treats all the other women around him.
Plot twist: he's not dense at all. He's actually in love with every woman who's in love with him, that's just how he acts with the people he loves.
Imagine that the way succubus magic work is that it makes the person affected act exactly like they would if they were truly completely in love with you. And that it 100% worked on him... and he ended up just treating her the exact same way as he treats all the other women around him.
Plot twist: he's not dense at all. He's actually in love with every woman who's in love with him, that's just how he acts with the people he loves.