Honestly, that was my same thought. I like Florian (actually not that much after what he did to Cain and Abel) but he's only really into us bc he can't get over his ex. Also, I've picked Cain, been with him since the first chapter, yet Florian still tries to make a move. If he really cared, he'd be happy that we're happy, and that's that. But instead he tries to decide what is "good for us" but in his own definition. Claims that he doesn't want to hurt us, but instead hurts the ones we care about, which does cause harm to us.
I have no regrets stabbing him. There's no way I'm cheating on Cain. I still remember how he reacted when we almost kissed Charles...