Need womanly advice....

Moms, please set me straight on this.

I'm sure you realize by now just how much I despise girls/women who take advantage of men. Don't get me wrong, I hate when men do the same. But it's the fact that these type of women have a "you-owe-me" attitude that...UGGHHH! I know it started in high school when I overheard the girls planning this type of behavior toward future husbands. I couldn't believe it. I wasn't raised that way. How could someone DO that? So anyway, I really need your words to ease my angered spirit.

Issue #1
When hubby sold his house a few years ago to a coworker, he felt badly for the woman since she was short $25k and the bank wouldn't lend her anymore. He lent her the money by lowering the cost, signed a quit claim, and had her sign a promissory note to say she owed him the $25k. Stupidly, the promissory note was never returned. Her word against his now. She called a few months ago to say she doesn't owe him anything and he can't prove it. She called last week to say she bought a new car. Nice.

Issue #2
I like my step son's girlfriend - she's sweet and treats him well but...just something I can't put my finger on. They're rather close and may eventually get married. My step son bought his first house. A great house that only this economy would have allowed him to afford. Since the purchase the girlfriend and her family have been hanging out decorating acting as if it's their house. She's much different around her mom and aunts. They're all snobby, like to be catered to, have the entitled attitude, and walk around the place with smirks.

It's causing fights between my step son and his mom. I can't say anything because I'm not related. Except one day when we were all there helping clean, I got tired of hearing the girl say her aunt was coming over to help decorate again. I finally asked if she was moving in. I asked if she was still in school working towards her architectural degree (I figured I could put her in touch with some firms) and she gave me some baloney about Biology and the more I asked the redder she got. Turns out she's been thinking of dropping out. Sure, why not, the guy has the house why should she make anything of herself now! Now she buys this $900 dog that she's keeping at the house! What, there aren't any in pounds worth saving? With what money? She's a hostess at a restaurant and should be saving the money she makes. My step son worked his ass off to get this house. I hate to see these leeches take over. I get so so so so angry and can't control it. I've decided not to go over anymore but hubby says this will only hurt my step son's feelings because he likes me. I can't watch this without saying something and I'm trying to stay out of it. This isn't even my son! What the hell will happen if this was?

I can see it starting to cause a rift between families that may eventually be joined. It's causing tension between hubby and I because he says his ex and I are overreacting and women aren't like that. I can't sit by watching this so would rather not be there. Then again, nothing has really happened. It's just I can usually read people pretty well....

So do I just stay away and act like an ostrich putting my head in the sand? Or do I just tell hubby and his ex not to discuss their concerns with me because I won't stand by quietly?