Temper sometimes make us spit words we wish that we could take back. Relationships break and leave scars. Regret won't do anything to heal those scars. Perhaps time heals a little, but the memory of those bitter moments sleeps in our subconscious mind will make relationships wrecked forever.
Controlling not to say any words that could make such things over a fight seems impossible, but it is possible. Whenever you see your loved ones, keep thinking about the good things that they have done to you, always. Each time you see, keep rolling all those loving moments with them. The moment when they helped you, cared you, made your life easy. Don't think of anything bad. In that way, your mind filled with good thoughts of the person whom you are fighting with, you can't hurt them.
Yeah! Easy to say, but I cannot do that either while fighting we just want to tear off the person opposite! While we fight, what we say out of temper is what actually how we feel about that person, subconsciously. Fighting will give us a chance to see a different perspective of a person. And thus understand his/her personality. A fight will make a relationship stronger and if it ends with a fight, it is good for you!