Be Clear About Expectations
Yes, you should be calm and kind. That doesn’t mean that you need to be a doormat, though. If a child is misbehaving and doesn’t have a parent correcting him, it’s fine to make your own rules clear. Tell them that they may not say or do that to you or your child after you’ve calmed yourself. Let them know that it isn’t ok, without scolding them. It shouldn’t take more than a few seconds to make your expectations clear before you let them try again.