Surprisingly, JennyDoe, the answer is quite simple. They fail to communicate and refuse to compromise. Often, people indulge in mind reading, and for some of us the only exercise we get is jumping to conclusions! For example, you might be sitting thinking about how you are going to make the next payment on your car, and naturally, looking a bit stressed. He says to you "What are you thinking?" and you reply "Nothing really". He says "Of course you are, just looking at you I know you are still mad with me because I had one beer too many last night" and storms off in a mood. In that scenario, you didn’t communicate, he jumped to a conclusion and ran with the story he had invented. The whole situation could have been avoided with good communication.
What that really means is learning to use specific skills to keep your relationships on course, and the first of these skills is honesty! Without honesty there can be no trust, and trust is 100% necessary if a relationship is to bloom and grow.
Please have a look at the website here:
It contains most of what you need to know, but like other things, you need to practice to get to be first class.