Any time you disagree, any time you challenge someone, any time you ask a blunt question…
Start by telling the other person you’re going to do this. And then check they’re OK with it.
As soon as they say yes, you can disagree, challenge them or ask that blunt question.
By getting their permission, they opt-in to hearing your comment. They choose to let you say your opinion. They’re ready for it.
Do this and you’re less likely to have a conflict.
And you’re more likely to get a good outcome that you both buy into.