Decide what you are actually telling them, before you say a word
This sounds obvious. It is not. There is a version of this conversation where you explain the whole thing, the timeline, the reasons, the moment you knew. There is another version where you say the marriage is ending and you stop there. Before you pick up the phone or sit down at their kitchen table, you need to know which version you are giving. Not because you owe them a curated story, but because you will be asked questions. His mother will ask questions. Even his father, who communicates mostly through sports metaphors, will ask something you are not ready for. If you have not decided in advance what you are and are not willing to say, the conversation will decide for you. Think about three things: what they need to know to understand the situation is real and final, what you are comfortable having repeated to your ex-spouse, because it will be, and what you actually want to protect, whether that is your privacy, your children, or your own version of events. You do not have to explain the affair or the drinking or the slow years of silence. You are allowed to say, simply, that it is over and you wanted them to hear it from you. That sentence alone is an act of respect. It is also, depending on the in-laws, an act of bravery.
Choose the format that protects everyone in the room
Phone call, in person, or a letter. Each one has a logic and each one has a cost. In person is the most intimate and the most likely to produce tears on both sides, which is not always bad. If you genuinely love these people, sitting across from them gives the conversation a weight that matches the relationship. It says: you mattered enough for me to show up. But in person also means you cannot pause. You cannot breathe. You cannot choose your words after you have already heard theirs. A phone call gives you a little more control. You can be in your own space. You can have notes. You can say I need a minute without an audience watching you need it. A letter or email is the choice people judge and sometimes the choice that is actually right. If your in-laws have a pattern of escalation, if there is a history of things getting said that cannot be unsaid, putting it in writing protects you. It also gives them time to process privately before they respond, which protects them. The format is not a measure of how much you cared about the relationship. It is a practical choice about where you can be the most honest and the most safe.
Say it once, clearly, and do not fill the silence
The temptation when delivering hard news is to talk until something lands, to add explanations on top of explanations until the other person looks relieved. Your in-laws are not going to look relieved. They are going to look like someone just changed the shape of their family, because that is what happened. When you have said what you came to say, stop. Let the silence be there. Let them have a reaction you did not script. What people often experience in this moment is the urge to apologize, not for the divorce, but for the discomfort in the room. Resist it. You are not sorry for telling them. You are not sorry for the news being what it is. You can be sorry it is painful without making yourself smaller to fill the gap. If they say something that stings, you are allowed to say that is hard to hear, or I understand you are upset. You do not have to absorb every reaction as though it is a verdict on you. One clear statement, a breath, space for their response. That is the whole architecture of the conversation. Everything else is just furniture.
Mark the ending of this relationship with something deliberate
After the conversation, you will feel strange. Not relieved, not devastated exactly, just strange. Like you have handed something over and are not sure you are done with it yet. Research consistently shows that almost every grief therapy that actually works includes some kind of deliberate ritual, a specific act that marks the loss in a way the regular passage of time cannot. The relationship you had with your in-laws was real. It had its own texture. The way his mother always sent you home with food. The particular awkwardness of his father that somehow became comfortable. That does not disappear, but it changes, and something that changes that much deserves to be acknowledged. You do not need to believe a ritual will work for it to work. You could write a letter you never send and burn it. You could take one last drive past their street. You could sit for ten minutes and list, specifically, what you will miss. Research on personal ritual as a therapeutic tool suggests the ritual that helps will be one that feels true to you, not borrowed from someone else's grief. There is no correct ceremony here. There is only the deliberate act of saying: this mattered, and now it is different, and I am marking that.
Decide now what kind of relationship, if any, comes next
Some people maintain a genuine warmth with their ex-in-laws. Some cut all contact. Most end up somewhere in the middle, which is its own complicated place to live. The time to make a provisional decision about this is before the conversation, not after, when emotions are running and everyone is improvised. If there are children involved, the calculus is different. Your children's grandparents are still your children's grandparents, and that relationship belongs to them, not to your marriage. You may need to make a quiet and mostly private commitment to not poisoning that well, even on the days when it costs you something. If there are no children, you have more latitude, but you still have to live with the choice. If you are feeling the kind of spiral that comes with all of this, where the practical questions keep looping back to the emotional ones, the piece on anxiety about the future after divorce addresses exactly that kind of circular thinking and why structured approaches tend to work better than open-ended reflection. For now: you do not have to decide everything today. But walking into that conversation with at least a rough sense of what you want the next chapter to look like will help you hold yourself together while you are in it.