Time to consider moving on. She is not the one to consider a stable long-term relationship with. She wants her bf for his looks, you for companionship and other guys for quick sexual gratification.

You are at the age where you are not young and not old. So you need to make a decisive choice on how to proceed.

Her preference for good-looking men and need to fulfil her sexual needs (by cheating) ahead of good companionship and good character is a major drawback for you. You are having a relationship with her at this point in time is just because her real bf is away on long-distance work.

Don't delude yourself that you will have a long and happy relationship with her. She is likely a "Alpha Widow" if she ends up with you. And cheat on you when the urge arises.

Hope you make the right choice and do not waste time with her.