Dear Mom and Dad,
My friend,LiLei,called me to his home to prepar for tomorrow'party,and I'd love to go.So I'can't have supper with you.Please don't worry.I will return as soon as possible.
your sweety
Lily
亲爱的爸爸妈妈：
我的朋友李雷叫我去他家为明天的聚会做准备，并且我很乐意去。所以，我不能和你们吃晚饭了，不要担心。我会尽快回来。