What shall I do?

[Sightseek]

Originally Posted by Indian Charlie

Who is more important to you?

You should consider telling her that you already have plans for your mom's birthday, and invite her along. If she's a cool chick, she'll probably be impressed with your loyalties and ability to keep a commitment. That can pay off later.

If she gets pissy about you choosing the dinner thing, well, that reveals what kind of person she is.

Pretty easy.