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 invite an old friend to a class reunion, use this factual base: give the event, date, location, relevant history, and what kind of contact the invitation involves.
Ask without assigning an obligation
Explain what you hope for while making decline, delay, or a different format genuinely acceptable. Offer a simple way to accept, decline, ask a practical question, or choose a lower-contact option. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Keep the ending honest
Do not announce their attendance, use relatives to persuade them, or make a public gesture before they agree. Respect no-contact, venue safety, custody, and legal restrictions even when the event feels important. Avoid future promises, guilt, flattery, or nostalgia that imply the recipient owes you access.