Relationship are hard for assholes. That's because assholes have lots of lust. I mean lust in the Buddhist sense where it includes not only sex but all desires. We want things from a partner. We want her to be with us at certain times. We want her to do certain things and behave in a certain way. And she wants this from us, because she's an asshole too. But relationships don't have to be that way. They can be much more fulfilling if we are prepared to let the other person do what they want, when they want, how they want. This only affects us if we are already invested in expectations of that person. Don't expect, just love, and let be. If they are an asshole and not respecting you, that is different. Don't accept any harm towards you in word or deed. But besides that, let them be.
There are fours things that will lead to blockage of the heart in relationship.
The desire to control/possess. The desire to be controlled/possessed.
The fear of controlling/possessing. The fear of being controlled/possessed.
I'm paraphrasing Gautama Buddha. This means that in relationship in order to show love, to be in love, in the true sense, we must not want anything from the other. Nor should we take action out of fear for the other's wants. Your only goal in relationship is to exchange the positive energy of love. This will increase both your energies and propel you both further into higher levels of consciousness/awareness. Expectation and desire are in opposition to love and will hinder your progress.
We've reduced the union between men and women to a kind of mind and energy battle where we all lose. When in reality, we are the complimentary energy the other needs to propel themselves to new levels of awareness. Sex is all about 'what can I get from you?' and 'how is she going to make me feel good?' This is ok. this is normal. But it doesn't need to be that way and instead of draining each other, you can fuel each other, and (with practice) you can do it without losing energy yourself. See my posts on ankhing and making love.
Relationships, especially sexual ones, can be an amazing guide to your own personal freedom. Let her be, and when this affects you negatively (I am hurt, I am jealous), let that guide you to where your own issues are. Because that is what those feelings are, your issues, not hers, not his. Contemplate those feelings, meditate on them, bring them fully to the surface and discuss them with her without blame. You can heal each other. Be sure you are healing her too. To give is to receive.
Ultimately relationship is a mirror for the self. A means to an end. That end being complete acceptance of self. You are in relationships that mirror your own self right now. The people in your life, and your relationships with them, are a guide to your self. Take a careful look at that.
Stop wanting, stop desiring, stop expecting, stop fearing, just love.
Don't be put off by 'personalities' you don't like. Hear the message. Lots of good info here