Shlishi, here I agree with you 100%. The truth can sometimes be very harmful to long-term relationships. If you find yourself speaking truth to your spouse too often, I think you should see a Rov or a marriage counselor. (“You” as a general term, not talking about anyone specific.) You see, truth leads to disagreements, disagreements ruin friendships. Lies lead to mutual accomodation, tolerance, and acceptance, albeit inadvertent, considering that you don’t know that you are tolerating the bad behavior because the bad behavior, in your eyes, dosen’t exist!
Gut Shabbos to all, Professor of Relationships Dovid