Back when my wife and I were still dating, she found a cheap ring she loved. It was just a normal jewelry ring with her favorite stones in it, not a fancy engagement ring or anything. But she loved it so much, she told me that if I ever proposed to her, she gave me permission to steal it from her and re-present it as an engagement ring. Which I did.

I felt bad about it though. I took the ring to propose, but my plans fell through and it took me a few more days to arrange a new proposal plan. She had forgotten all about our conversation, so the whole time she was tearing the house apart, looking for her favorite ring. She loved that I "found" it and gave it back to her with a proposal.