A total lack of Communication and respect.

Always communicate. Communication is one of the most important things in any relation, especially between lovers. Communication is the thing that takes away doubts, incertainties, grieves and annoyances. Communication is also the thing that tells the other you love your partner, that you care about your partner and that you want to be with your partner.

Communication and respect need to go hand in hand. Otherwise, communication can become a weapon.

So respect is the other part of the foundation to build a relationship upon.Always respect your partner, always treat your partner with the utmost respect. A relationship where one of both partners doesn't feel respected, is bound to fail.

Respect means, treating your partner with respect. Respect in a relationship means, also treat yourself with respect, and make sure your partner treats you with respect. A relationship where you respect your partner, but your partner totally disrespects you is an unhealthy relationship.

In my previous relationship, I was totally disrespected, in many ways (the woman still disrespects me). And, there was no way of communicating on a normal level, so at one point in time, I had to stand up and demand respect for myself. That's when the relationship ended, on the first occurence of me not blindly following and pleasing her demands.