It seems to me that most Americans have one or more people somewhere in their family or friends that they just can't get along with. The way it feels is like, "I just don't feel comfortable around them. I can't be myself. They make me feel and act crazy, so I prefer to avoid them."
To create and maintain healthy relationships with our friends and family members, we all need three skills. The first two are simple to define mentally, but they aren't always easy to do emotionally.
First we need to be able to show love. That includes showing behaviors like smiling, laughing, saying hello and goodbye, please and thank you, giving compliments, making time to be together, sharing what's going on in your life, accepting their right to make the choices they make, confronting them with truth that hurts but helps to set them free (like, "You're acting a lot like an addict there"), believing the other is basically a good person, helping the other out, and asking for their help.
Second, we need to be able to detach, to let go, to stop showing love. We need to have our own life to live, things that we can enjoy doing quite independent of whether the other person approves, helps or funds us, or comes along with us. This requires us to believe that the other person likewise has their own life they at times need to live quite independently of us.
The third behavior, unlike the first two, is not really developed in childhood. It is the ability to recognize what ways of relating we will and will not engage in. It means knowing when to love and when to let go, to fish or cut bait.
This is called setting boundaries. Most people never learn to feel comfortable enough to do this with loved ones. They allow themselves all kinds of ways to relate that aren't healthy, and therefore they can't in good conscience detach when others are doing the same things.
Professional counselors refer to the more common relationship mistakes as "dysfunctional behaviors." If this sounds too much like psycho-babble, you can call them "things that just don't work" to bring peace in a relationship long term. They may bring a short-term relief of tension between people, but they produce distress in the more responsible people, and they enable (help to maintain) irresponsible behaviors in others. The peace is always short-lived, because the overly responsible people soon get worn out and have to complain or change.
Here's a good starter list of dysfunctional behaviors, actions that create bad (not peaceful) relationships. These are actions that people use to take their responsibilities off their shoulders and place them onto yours. Because these actions indulge irresponsible people and exhaust responsible ones, all your loved ones need to know that you don't go along with:
When someone wants you to excuse one of these bad habits, you need to be prepared to use all three relationship skills at once and say something to this effect:
"You know I love you. You're a wonderful person. I love doing things for you, and doing things with you [this is skill # 1]. It isn't really like you to (lie, cheat, hit, whatever). I don't go along with behaviors like that in any of my relationships [skill #3]. I need you to apologize to me for that, figure out what inside you caused you to act that way, and convince me that if you ever do this again to me or my loved ones, you will do what I would do: immediately apologize and start making it up to the people you've hurt to teach yourself not to do these things anymore. So until you choose to clean up your mess, I am going to keep my distance from you emotionally. I won't be sharing much of my heart, my calendar, my wallet, my body, or my good times with you [skill #2, the teeth of detachment that are needed to make any deal stick.] We can resume our usual closer ways of relating as soon as one of us changes our standards to fit the other. We'll see how it goes, and in the meantime, I'm keeping my distance from you, unplugging myself, and going on with the parts of my life that don't make me violate the rules I live by, so I can keep showing love and respect for others and myself. Have a good day."
One final warning: don't try doing this until you can feel good about it regardless of your loved one's response. If there's a way they can make you feel bad, they'll find it, and you'll be the one to change your standards back down to theirs. That's the bad news.
The good news is on the flip side of that coin. When you not only act better but feel better about yourself, it will show, and your friend or family member will feel worse until they change. Sure they may change for the worse in the short run, but if you hold your ground with peace of mind, it will make them feel worse than ever, until they finally either love you or leave you. Either way, think about it: in the long run, you're better off, and so is the world.