You’re bringing up other mistakes
You’ve already made a list of all of the other things this person has done wrong. As a backup plan, in case they do nail the apology for this particular incident, you have compiled a detailed account of every other way they’ve ever wronged you. This person doesn’t stand a chance. They are approaching you, thinking they’ll say the perfect thing to get out of trouble on this thing. Little do they know you’re about to open a long scroll of paper and detail what they did wrong on February 12 of 2019, and your birthday in 2015, and that one vacation you two took in 2013. You will drown them in a log of mistakes they didn’t even know you were keeping track of.