One with the negative vibes
She would never encourage you in your endeavour. No matter how hard you try to put your best feet forward, she would try finding chinks in your armour.
Her negative outlook towards life in general won't make for a happy place.

One who is selfish
It is difficult to stay put in a relationship with someone who is selfish.
All that would matter to them is their well being and their sense of happiness.

One who is a compulsive flirt
Even though being a little flirtatious with someone else apart from your partner is not harmful. But when it leads to unnecessary complications in a relationship, it is better to ward that off.
Few people are hard wired that way and cant let go of their flirtatious image no matter what the stakes.

One who is entitled
People who exhibit these characteristics believe that the world is at their feet. And everyone has to bow down to their whims and fancies.
Being in a relationship with such a partner, would never give you a feeling of being equal in a relationship.

One who craves and loves spotlight
It will be hard to keep up with someone who is in the constant need for gratification and validation from others.
Such people love to live in a bubble which is far removed from the real world.

One who loves partying
They have no apparent responsibility towards anything in life. Partying is the only purpose for their existence is what they like to believe.
While being a party animal is not wrong, but being just that can be a little boring.

One who is commitment phobic
No matter how long you have been in a relationship or no matter who steady you have been as a couple. One who is phobic to commitment would never honour your proposal for marriage.
You can't fault them for being what they are, you could only set your expectations correctly.

One who loves to gossip
This isn't just gender specific. There are men who love to gossip just as much a woman would like to.
But their life beyond gossip is nothing but a bunch of stories about someone, something, somewhere.