The blending of families and co-parenting styles is not easy. Two houses, parents and step-parents means a lot for your kids to keep up with. It can be a lot for the grown-ups too. This is especially true if you have a difficult ex to contend with.
I'll admit that I am truly fortunate to have an amazing co-parenting situation. So, it saddens me to see so many families who don't. I see so many mothers and step-mothers make it harder on themselves than it has to be. They focus on the ex-wife or girlfriend and what she's doing or not doing, when conflict arises.
Additionally, their attempts to make their husband see that giving in, coddling, allowing tantrums is not effective parenting. When in fact, a lot of men do these things out of guilt and simply don't want to be the "bad guy" in their child's eyes. Not that it makes it right, but this is one of the most common reasons why. Dad could be in effect partially responsible for the behavior, so that needs to be addressed with him first.
Think for a second, if you took all of that frustration with the ex or your significant other and channeled it back at yourself and your family life in a positive way; keeping the focus on you, the kids, husband or significant other and what's going on in your home. Basically, stop worrying about how much the ex spends on new clothes or (insert here) whatever you complain about the most. It's pointless really, because it's largely out of your control.
Giving your precious energy to try to understand the selfishness of the ex is futile. Don't waste your thoughts on how she lives or who she dates, unless it directly impacts the care of the children in an adverse way. Her ability to empathize with your plight (if she is combative) is a wish on your part and you will never be able to change the free will of another person.
So instead (and this will be the hard part) meet her where she's at as a human being, have empathy for her in that perhaps she's not fully equipped to be a parent. Forgive her for choosing laziness, a boyfriend or selfishness over her children.
Also consider that this other woman gave this tiny human life. This is her biggest responsibility and that entitles her to care about certain things that go on in your home. And maybe she's not the pain in the ass you think she is. Maybe she's just nervous or has a little of her own guilt that she's not there sometimes for moments that you are now witness to.
As for dad, forgive him too. He's most likely giving in to still feel like he's getting quality time with his kids. A majority of dads don't get the parenting time that mothers do. Without realizing it, they take the easy route of momentary happiness, and don't consider the long-term affect. However, he is not off the hook. This is a time for a sit down with him. Guilt, trying to please the child or non-discipline, for fear the child will like him less is not an excuse for letting kids throw fits or refuse to follow rules.
You are the grown-ups. They are the children.
A united front is in order because your house, so your rules. Consequences will follow for not complying. Rules and boundaries are to be determined by the two of you and not influenced by the seven year old who might lose his mind when you say no.
After discussing with your spouse, have a family meeting. Inform the children of whatever the new standard is and what consequences will follow. Post a hard copy that is visible in the home. This way there are no excuses when punishments are doled out.
Allow the kids at this time to openly speak about the things that are bothering them as well. Don't judge -- just listen. They do deserve to be heard.
Ultimately, the rules are in your hands though. As a step or full parent, you must consider that sometimes behaviors are "normal" or age appropriate and others are a cry for attention, the result of brain washing from the other parent or they are straight up not adjusting to blending. If you get to the point of serious upset in the home, it might be time to consider family therapy.
A blended family is a team effort, but it is also about individuals coming in with perspective.
Step-moms: Despite the fact that you didn't carry this child for nine months, you are in the home, part of the family and you are to be respected. You now carry them as part of your every day. Your love is not less. Your word is not weaker. You are a bonus in their lives and they yours. Feel free to take those last four sentences and frame it for your home as a reminder.
Dads: Being a father is biology. Being a dad is so much more. It sucks that your children live in two different homes. I get the psychology behind feeling like a failure (you're not by the way) and trying to overcompensate by giving in more that you say no.
Saying no more than you say yes is your job though. Unless you plan on having daily battles of epic proportions over the small stuff or what's simply expected of them, get used to saying it and stand your ground. And stop letting them tell you what happens at mom's house. They will play on your guilt if you make it easy for them to do so. I know you love your kids, but discipline is love. Have step-mom's back while she's feeling her way through this new dynamic, too.
Moms: Support dad and step-mom in what is acceptable in their home. So long as your child isn't being seriously harmed, ease up on trying to have control. You just can't have a say in everything. You also need to get the entire story before you flip out. Kids get caught up in their emotion and forget the adult logic behind the situation. They leave out important details sometimes, whether on purpose or not.
With forty percent of U.S. households being blended families that means that about 100 million of us have a step-situation. Now more than ever, teamwork type co-parenting will prove to be absolutely vital in raising the next generation of men and women. "It takes a village" just took on a whole new meaning.