In-laws are a tricky relationship to manage and part of how you approach them depends on different variables like how often you see them, how your partner supports you vs. them, and how severe their behavior or boundary-crossing is. But here’s a general outline for how to state a boundary to your in-laws (assuming you want to maintain some sort of relationship with them).
1. Call out the possibility of offense “I have to say something to you that may be difficult to hear, I am worried it may offend you, but it’s not meant to”
2. Emphasize their good intentions “I’m sure you mean well when you make comments about our parenting, I just know you love our kids and want the best for them...”
3. State the boundary clearly i.e .” when you share advice or make comments, it takes away from our enjoyment of just being together. We know you have value to add to our parenting and we will come to you when we need your input.”
4. Express appreciation for following the boundary “we really appreciate you hearing us out and making this change.”