dear XXX,
I’m terribly sorry that I didn’t attend your party which I had promised already.I really wanted to go.How is everything going?I’m sure that the party was exciting and you had a lot of good to eat,huh?
It's such a pity that I couldn’t enjoy it with you.At that day,someone told me that I had to finish (…..您来填写).I couldn’t help expecting to get away of the mess and to rush to the birthday cake.
Anyway,I want to say,happy birthday to you!And… your present!Though it’s still here,but we will have a good time next time when I see you.
yours,
你的名字
月 日