You are within your rights. The fact that they gave you such a hard time, shows me that you need to do this more often. That's how you condition them to a new standard of what is normal. Try to enjoy your weekend. Keep your resolve. They are lucky you are as caring as you are, but their behavior needs to be curbed.

This forum is gets lots of threads started by people with parents like that who never figured out how to deal with it properly. I'm glad that you do know how.