To reject invitation to a personal event
[Date] [Name] [Address] Dear [Name] Thank you very much for inviting [partner] and I to your [personal event] on [date]. We were really looking forward to it but, sadly we will not be able to come because [reason]. We are really disappointed but do call us after the [personal event] to give us all the latest news. We hope everybody has a great time. Yours Sincerely [Your Name] [Your Title]