When my wife told me this I politely told her to go F herself. Because she was making assumptions about my ability to forgive her based on her inability to forgive people. That I was emotionally stronger than I ever imagined possible, and I was upset with her determining a future of failing based on her flaw perceptions of me. I told her that if our marriage ended, it was her choice but to never end it because she didn't think I could handle it.
Excellent. I tried saying something like that early on, but it didn't come out quite as awesome as what you said.