Eh, I think it’s more like they’re addicted or stuck in a particular fad
Think of how much “modern art” is admired even if almost no actual skill or throught is really put into it
Honestly, I doubt he even ever fell in love with her, so either he was being hyped on Far Left Politics or she had blackmail on him or more improbably, got HIM of all people into a moment of weakness and psychological terror and pressure
Honestly, if you're gonna be evil or just amoral, you have to at least be smart to preserve yourself
I think he's talking about Discworld by Terry Pratchet