There are three things in speech that ought to be considered before some things are spoken—the manner, the place and the time.

Being right about the content is only a third of the job. The same sentence can land as care or as an ambush depending on how you said it, where you chose to say it, and whether the person had the capacity to hear it just then. Most conversations that go badly were not wrong in substance; they were delivered into the wrong conditions.

Before the difficult one this week, settle all three deliberately. Not in the corridor, not at the end of a long day, and not in front of anyone else. Decide your opening sentence in advance, and pick a time when neither of you has somewhere to be.