First, bear in mind that emotional sadism may simply be a step too far for him… being a kind person isn’t something he needs to struggle to overcome. Don’t try to make him a worse version of whatever he is… decent men are hard to come by.
But with that said, I was once where he’s at, and I can tell you a little secret which will unlock any cruel and manipulative streak that might run through him. It’s simply this:
You’re the problem.
Because unfortunately, he likes you. He respects you. He thinks you’re a special person deserving of all his affection and generosity. He believes you know how to feel things like a normal girl. He is, in short, confused by who you seem to be.
So fix the problem you’ve created and make sure he knows what you really are. Take the time and do it right… walk him through your expansive gallery of shame and inadequacy, and show him how wet you are while you describe each of the exhibits. Make him understand that there’s nothing he can say to you that you haven’t said to yourself 1,000 times, and how hearing it from his lips will simply relieve you of an eternal burden. Promise him that his most hateful whispers will always be shouted down by your love.
And then prepare to reap the whirlwind.