Nice Guy Provider or Just Plain Sucker?

Excerpt from a post:

My girlfriend of one year has two kids (son 6, daughter 4) from two "thugs" (her own admission). Neither of these lowlife losers have been remotely active in their kids' lives. When she was involved with these losers, then she provided everything for them (money for beer, movies, clothes, food, etc..). She admitted that she literally took care of these losers because she truly loved them and really wanted to make those relationships "work".

As a result, my girlfriend claims that she will never be taken for granted by another man again. Initially I understood her viewpoint so I continued to love, respect and spoil her as I've done with past girlfriends. I've been especially kind and loving to her kids as well (playing Santa at Christmas, birthday presents and spending quality time with them).

Last month, I asked my girlfriend to "loan" me some money ($250.00) for a late car payment. I knew that she had the money to loan to me so I told her that I would repay her on the following Friday. She simply said, "No, you need to work something out !" Angrily I reminded her that I've done more for her than both of her lowlife sperm donors together. I reminded her that I intended to repay her for the loan. Finally, I asked her to leave my home so that I could cool down.

Her loser sperm donors got the royal treatment and treated her like crap. I "step up" and treat like a real man should and she abandoned me in my (temporary) time of need.

What should I do?