put the mouth on someone
put the mouth on (someone or something)
1. To praise someone and bring bad luck to them as a result. I don't want to put the mouth on you, but I think you have a real chance at winning the championship this year! Not to put the mouth on myself, but I've been flying past my sales quotas each month.
2. To speak negatively or unflatteringly about someone or something. Why are you always putting the mouth on Tiffany? You don't even know her that well! Not to put the mouth on fast-food restaurants, but they aren't exactly the dream job for most people.