Tact is just honesty that checked the map before driving over to your house.

Tact is not a softer truth, it is the same truth delivered with attention to timing, place, and how much the other person can take right now. People mistake it for dishonesty because it involves restraint, but nothing is withheld except the version that would land badly. The content is unchanged and the route is chosen. Choosing the route is part of caring whether it arrives.

Before saying the hard thing, ask three questions: is now the moment, is this the right room, and how much at once. Then say it fully, but say it there.