Backbiting indicates a lack of respect and love for one's mate. A statement such as "he puts a lot of salt in the sauce” or “he wakes me up before time,” may appear trivial, but they can spoil a relationship because such statements are generalizations, not fact.
Your mate can feel insulted and betrayed. He will try to defend his position, and you end up in a heated argument. You are in effect generalizing your mate’s flaws, which is indefensible.
Telling others confidential matters makes your mate feel insecure. A mate may conclude that the offender can spill more beans or open other cans of worms. You should avoid backbiting to help your relationship to grow and mature.
Never call your mate lazy, stupid or selfish. Your mate may conclude that his entire personality can be summed up by your description, which is mean. Surely your mate has some positive things. He may excel in certain situations such as sports, singing or painting. He could be holding on to his job nicely and may offer you advice once in a while. Labeling him selfish, stupid or lazy would be far from the truth.
Insulting speech strains a relationship, resulting in dire consequences. Cutting words from either mate can eat away a relationship. Bit by bit the ties erode until the relationship becomes unsustainable. Once said, you cannot swallow back your words. Even when you say sorry, you can't erase the damage.
It is like throwing a stone against a wall. The damage will stay on the wall. The same with insults: the injury does not go away. It remains in the heart of the offended mate. Some people say that they can forgive and forget. But they do remember. They accept the damage and decide to let the offense rest. Safeguard your relationship by refusing to backbite your partner.