This negativity can manifest itself in overt verbal or physical abuse, or be passive aggressive, which is more subtle. Passive aggressive behavior always gives the perpetrator the excuse, when confronted, that they were misunderstood. Not only will they not respond to a legitimate issue, but they are making you feel like you are the one with the problem. True love is not formed by one person ratifying or paying homage to another person's inaccurate view of reality. However, many relationships are constituted with a quid pro quo.
Gold diggers are obvious quid pro quo relationships.
Many of the behavioral issues described here are borne of lack of honesty, lack of nurturing, lack of empathy, etc. Alternatively, the person with the obvious problem may disguise the issue, alter his or her personality, until a commitment is made. By then, the marriage can be consummated. Alternatively, a weaker person will accept, ignore, or rationalize progressively worse behavior or treatment from the other and even blame themselves for the behavior. People need people for myriad reasons.