Mercy is not pretending the line was never crossed.

Forgiving something does not require rewriting it. Mercy that depends on everyone agreeing that nothing much happened is not mercy but a shared silence, and it usually leaves the wronged person carrying a truth they are not allowed to say. The line stays where it was. What changes is what you choose to do about it.

If you are letting something go, let yourself name it accurately first, at least privately. What happened, what it cost. Then decide what you are releasing and what you are keeping, such as a changed arrangement or a limit. Mercy that has looked at the thing clearly tends to hold much better than mercy built on not looking.