Account for the relationship as it is now
Use a tone that fits the present relationship, not the closeness, authority, or access that existed in the past. For a message about how to apologize for sharing your partner's private news, use this factual base: name your behavior, its likely practical or emotional impact, and the agreement or trust it affected.
Ask without assigning an obligation
Explain what you hope for while making decline, delay, or a different format genuinely acceptable. Offer a specific change the other person can observe and ask what repair would actually help. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Keep the ending honest
Do not explain away the behavior, bargain for affection, or use gifts to skip accountability. Respect separation, no-contact, and safety plans, and use professional support when coercion or abuse is present. Avoid future promises, guilt, flattery, or nostalgia that imply the recipient owes you access.