Keep the message proportionate
Use the shortest explanation that still tells the truth about the event, impact, and current position. For a message about how to apologize for making a friend the joke, use this factual base: identify the moment, the impact on trust or inclusion, and what your friend should not have had to carry.
Give timing that can be trusted
Give a realistic date, a simple option, or a direct yes-or-no question and avoid vague promises such as soon. Offer a repair that matches the harm and show how your behavior will be different. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Close the loop without drama
Do not use shared history, mutual friends, or public gestures to pressure a private response. If contact is unwelcome, stop and avoid using mutual friends as messengers. A calm ending is more credible than a warning, a grand gesture, or language designed to provoke a response.