Funny birthday cards

My boss's birthday is coming up and so I was looking for something funny to get for her. She has a great sense of humor, but still... don't think I should get her these!

FRONT: Happy Birthday!

INSIDE: There. I came to your party. Now you owe me.

FRONT: Happy Birthday! Here's to another year...

INSIDE: ...older than me. Sucks to be you.

FRONT: Happy Birthday.

INSIDE: You've just turned an insignificant age that nobody really cares about.