I appreciate it. - A fake thank you that hides the fact you're about to tell so

A fake thank you that hides the fact you're about to tell someone to go to hell. It's like a nice cup of coffee before you get poisoned.

I appreciate it, but I’m still going to tell you to fu*k off.

I appreciate it, but I’m not done with you yet.

I appreciate it, but you’re still the worst.