Have you ever said, "I'm tired," when you're not really tired at all? Maybe you just don't like what you're doing at the moment and instead making this feeling explicit, you water it down with, "I'm tired."
Do these slips have any reflection on a person's rational status? Are we in thinking mode, or is it just an automatic response the way "ouch!" is whenever we stub a toe? Further, are these expressions symptomatic of an underlying moral problem? One should say how he/she feels, and so anything short of this would therefore fall short of a moral imperative.
Considered another way, it may actually be a sign of moral virtue. If you have your friend's feelings in consideration, you will likely "blunt the strike," so to speak. Your desire for his emotional well-being is morally praiseworthy, but do the ends justify the means? Or, is this question entirely misplaced, since your friend's well-being is an end in and of itself?
Ethics is tricky. I think I'll stick to the Golden Rule. That famous guy said it. What was his name? Oh, yeah. Jesus!