Dear Sarah,
I hope you are doing well. I am getting in touch because I have some disappointing news regarding my upcoming trip to visit you in Sydney next month.
Unfortunately, my brother has just announced his engagement, and he has decided to hold a surprise celebration for his fiancée on the exact dates I was supposed to be away. As I am helping him coordinate the logistics for the party, it is essential that I am here to support him during such a significant milestone.
I am incredibly sorry to have to change our plans at the last minute. I know you have already taken time off work to host me, and I feel terrible about the inconvenience this causes. Please accept my sincerest apologies for letting you down.
I would love to reschedule if you are still open to having me. Would it be possible to visit in late October instead? I have checked my calendar, and I am completely free during those weeks. Please let me know if those dates work for you, or if another time would be better.
I really hope we can still make this happen.
Best wishes,
James