Thanks everyone.
I have been stepmom to the two girls for 11 years so I know that they really don't remember a time when I wasn't around. I know that many stepmoms feel this way, but I really feel that I was more of a 'mom' to the girls when they were younger than their own mother. I don't blame their mom (too much, anyway.

) She was young, had the girls in daycare while she worked then often with a babysitter while she went out with her friends during the 15 days per month that she had the girls. I was lucky enough to be able to stay at home when we had them as I worked as a relief pharmacist and set my own hours. I potty trained the youngest, taught them both to read, and generally did all the things that my mom did with me. DH and I worked well as a team and I got all the 'support' that I needed from him.
Fast forward to about a two years ago..... Their mother, now married, quit her job and has decided that she wants to be full-time friend to the girls. She has always maintained that she would rather be a friend to them than a 'mean mother'. Anyone hear warning bells going off anywhere??? Now that the girls are older, they stay with their mom for the school week and we don't see them nearly as often since they also want to spend time with their friends.
The oldest has now become a teenager and going through all that entails with moodiness and acting out, etc. DH doesn't want to spend the little time with her having to discipline her for her behavior, but it is really out of control to the point of writing obscenities all over her bedroom wall. (Dh's attempt to explain that was that we told her she could decorate the room however she wanted to!!!) She has even been grounded at her mothers, which is unheard of, for telling her mother she will be with a friend and then going somewhere else. She has become increasingly disrespectful to the point that last weekend, she refused to do what I told her and said she didn't "have to". DH comes home and is angry with me for making him handle the situation, which in my opinion he didn't do anyway by just telling her that she has to listen to me. I feel guilty for saying this, but I don't even want the girls around. Their little brothers see them getting away with things because I don't want to cause a big fight with DH. And DH doesn't want to cause a big fight with the girls. The girls are just happy to do what they want!
I understand DHs point, but I'm getting tired of being disrespected, being angry with DSDs, angry with DH, and dreading the weekend when they are here. I know that I'm not the only one that goes through all this, but I'm the only one that I know in this situation.
After rereading my post, I think a big part of this is DH. Apparently, that is the problem I need to address first. Hmmmm...anyone know of a "Evil Wife" support site?
Thanks for letting me vent and letting me know that I'm not totally alone in this.