Hi, here's a brief history:
My partner and I have been together about two and a half years. He has three kids, I have four. Both of us are custodial parents, him all the time. We don't live together, but are neighbors in an apartment complex. His kids' mom has sporadic contact with them, so for all practical purposes, I am their "mom" in daily life.
We are both students. When I'm done with my bachelor's degree, I'm planning on applying to dental school, which means moving at least two hours away (if I get in there), otherwise to another state. I've been pushing hard for us to move together, because I don't think it's at all realistic to consider having a family two hours away, as a dental student. I feel that mothering is a daily job, or at least several times a week. Plus, his kids have been through enough with their own mom- I don't want them to be abandoned again, especially not by me! He agrees, and we are planning to move together in a year and a half.
Ok, but slow down. As much as I love those three, they fight SO much, I am having serious second thoughts about subjecting my kids to that level of conflict in their own home. We rented a house for Christmas weekend, and just seeing the seven(!) of them together, it really hit home what this would be like. DP's kids require constant intervention and attention. They tease each other, hurt each other physically, scream, call each other names. Not only that, but they are extremely disrespectful to adults, too. They whine, scream, throw tantrums to get what they want. They will not follow instructions, demands, polite requests, anything. They laugh and jeer openly at my partner when he tries to discipline them. They do not go that far with me, because I will take them by the shoulders, look them right in the eye, and use my stern voice to tell them that I will not tolerate that behavior.
DP, bless him, does not have a scary, I-have-a-limit-and-you-just-reached-it mode. In fact, he generally ignores their awful behavior, which is, of course, why it persists. He thinks their fighting is normal, and the noise just doesn't bother him. He hates their disrespectful behavior toward himself, but he doesn't do what it takes to stop it. I've tried to share my own strategies that have worked with my kids (they fought like that when they were 3-5 years old), but he thinks my kids get along because they're older. He refuses to believe that he could be doing anything to encourage their behavior. At times he has gotten really offended by my attempts to influence his parenting, and I have backed off.
When we are together, I play the disciplinarian. Not a great role for a step mother! It doesn't work very well- they improve, but I just don't have the same influence I would with my own kids. At Christmas I spent so much time redirecting, calming, correcting, disciplining, entertaining, and comforting his three, it was really noticeable to me that I didn't interact that much with my four. I hardly spoke five sentences to my 13 year old! This isn't fair to my kids, and it's just not going to work.
I have to bring this up with my partner, and I'm not sure how to put things so he won't just hear "your kids are monsters and you are a terrible parent". This is doubly hard because his kids are always with him, and they won't leave him alone for more than about five minutes.
I don't know if it goes without saying, but I should add that his kids have been through a lot of tough experiences, and they have a lot of personal issues that contribute to their behavior. However, DP does not think this is the case, either.