Literally everything I tell my son that he needs to do his grandfather (who we live with) tells him…

Literally everything I tell my son that he needs to do his grandfather (who we live with) tells him to do the opposite. He needs to eat, I told him he couldn't go outside, so what does grandad do? Picks him up and takes him outside saying "we'll just be a little bit." He does this with everything.. when I have to brush Phillip's teeth, when phillip has to go to bed or go down for a nap. So my question is.. would this annoy anyone else? Or is it just my hormones that are making me sensitive?