So called mutual friend has feeling for my husband!!

My husband and I fell in love "at first sight". Unfortunately, we were both addicts in recovery but we couldn't help ourselves. I wouldn't call the people we hang out with friends more like acquaintances. Anyways, there is this girl whom kind of attached herself to my husband and I. In my past relationship (of over 6 years, he cheated on me 5 times and told me about it each time) Don't ask me why I stayed, I was young and naive). My husband is awesome and I have never had any reason to feel that jealousy sting in the last ten years until recently. Our so called mutual friend has come back into our lives and I don't like it. I've told my husband that she makes me uncomfortable and is very disrespectful towards me. She only always calls him and uses his kindness to get what she wants. For example, a month ago she asked to borrow money, my husband said that all we had was barely enough for us to get thru the week, but she pressed on and he finally gave in (she made sure to do this while I was in the shower and couldn't hear). She promised to pay us back the next day. It has been a month and not one phone call to say at the very least that she didn't have the money. Wait, she has called four times in fact to ask if we could help her score. Never once mentioning the money she owed us. Frankly, I just would rather her keep the money and lose our phone number, but for unknown reasons to me my husband lets her get away with this. We have fights about her all the time and each time he insists that Im paranoid, crazy, or jealous. He insists that there in nothing going on and I have never had any reason not to believe him. Maybe I am, but there have been girls in the past that Im totally fine with. I honestly believe that she has feelings for him, I can see it but my husband can't (call it female intuition) nor can he see the way she pretends to be my friend but only asks about me to make it seem like she actually cares. I mean she does this all the time and Im way past my breaking point. I love my husband more than anything and I don't want to leave him, but I don't want to keep fighting about this girl and sounding like a crazy, jealous wife. Someone please tell me whether Im being crazy or if I actually have a reason to be upset.