Dear Mr. and Mrs. Thompson,
Thank you so much for the kind invitation to Chris’s surprise birthday party next Saturday. It is such a thoughtful idea, and I am certain he will be absolutely thrilled to see all his friends gathered together, as he has been talking about wanting a proper celebration for months.
However, I am incredibly sorry to say that I will not be able to attend. I have a long-standing commitment that weekend which I simply cannot reschedule, as I will be out of the state for a family wedding. I am genuinely disappointed to miss out on the big reveal.
Since I cannot be there on the night, I would love to make it up to him. I am planning to be back in town the following Friday, so perhaps I could take Chris out for a celebratory birthday lunch at that new café he likes? Please let me know if that works for his schedule, or if you would prefer I drop by your place later that weekend instead.
I hope you all have a wonderful evening celebrating.
Best wishes,
Alex