Divorce Support Forums: What would you do?

Hello. I am new to the board and I really could use any good advice that you all can give. Here is the situation: (Please by patient, this is a long story.) I have been married to my husband for almost 11 years now and he has one child from his first marriage, I am his second wife. We have 2 children together, aged 10 and 6. My stepson is now 18 years old and has turned out to be a fine young man. Anyways, the problem we are having is the ex wife. I really don't know what to do anymore. It has been a long road dealing with her and her every request. My husband has always faithfully paid his child support and all the extras that he was asked to pay on top of that. He has paid for trips, braces, class rings, pictures, gas, clothing, etc. on top of support. She seemed to always be calling him wanting more and more money even though my husband paid child support. It has driven me so crazy! I didn't always agree with all of the extra things that we paid, but I was afraid that if we didn't then my stepson would go without and I didn't want that. Well, now that he is 18 and the child support is over, she is still calling my husband wanting more money. It is driving me crazy! We are now giving money directly to my stepson to help cover his gas and clothing and other extra items. I feel that she should not be calling my husband anymore and should leave us alone. My husband is a very nice guy and he will not just tell her to go away! This is what is bothering me so bad. She is calling my husband and asking for money for her bills and he won't tell her to stop! He just says that he is not giving her money so don't worry about it. Am I overreacting? I feel that now that my stepson is an adult and we have a great relationship with him that whatever we do for him is our business and she should not be butting in and telling us what we should pay and asking us for money for her rent! This is really taking a toll on our marriage and I am at a loss. All these years she has been really extremely difficult to deal with and I just couldn't wait for the day for my stepson to be grown so that we wouldn't have to go through her anymore. Will if ever end? How do I deal with this? She is driving me nuts! I feel that the only reason that she should even call my husband is if there is an emergency with my stepson. We communicate with my stepson just fine without her! I know that she will always be his mom, but I am tired of her crap. I know that I am going on and on and I am sorry, I just don't know what to do. Please give any advice that you can. Thanks!