Write a formal letter to an ex, expressing genuine remorse and apologizing for specific mistakes you made during the course of your relationship. Your letter should be clear and concise, and should avoid any blame-shifting or excuses. You may wish to include personal anecdotes or memories, but make sure they are relevant to the apology and not simply a reminder of happier times. Consider the tone of your letter carefully, striving for a balance between sincerity and respect for your ex's feelings.
This prompt doesn't seem malicious.