Dear Eli:
I am so honored that you invited me to your daughter, Lola's wedding last week. I really want to go and witness this happy and sweet moment of the new couple's life on the afternoon of Saturday. However, My elder sister is moving to a new house on the same day, and I have promised to help her. So I am afraid that I could not make it. But I will visit the new couple if it is convenient for them.
I'm sincerely sorry again. Please do give them my best wishes. And May the wedding go smoothly and the new couple live a happy life.
yours, Nancy