lui dire la vérité
I don't have the desire to tell him the truth.
Je n’ai pas envie de lui dire la vérité.
Afraid of hurting his feelings, I didn't tell him the truth.
De peur de le blesser, je ne lui ai pas dit la vérité.
Why didn't you tell him the truth?
Pourquoi ne lui as-tu pas dit la vérité ?
You had better tell him the truth.
Tu ferais mieux de lui dire la vérité.
Dis-lui simplement la vérité.