My advice is to always be the bigger person & NEVER say anything negative or derogitary about that person or that relationship to your children. Make sure ex wifes new partner knows not to interfere, but that there is not to be any negativity between you.

don't we wish there was a step to step giude to men, kids, and ex's. My ex has had a baby we just sent them prezzies. got no thanx of course. but the way i,ve dealt with this over the years is to respect their relationship and just deal with the kids issues. Ignore what the partner says. Funny how the partners seem to have a lot to do with the ex's decissions hey. Just be a gd person to all involve. It's a very hard issue and can be so frustrating at times. Good luck with it, big hugs

My brother and his wife split and it was not a friendly time.  They fought and it was not fair on the children, my brother even stopped speaking to us (parents included) because we refused to stop speaking the mother of his children.  Fortunately this has now passed and everyone is much more civil to everyone else.  My original sister in-law couldn't stand having to meet with with the new (then, now 2nd wife) girlfriend, but we advised her to always take the high road, which she admirabley did.  This made it hard for the new partner and my brother to find fault with her.  Finally they brought in a communication book that came and went with the kids.  If anything was to be changed or asked, it went in the book.  This worked well during the "hurt feelings"and volitile grieving part of their split and saved the kids from wittnessing and ill feelings between any of them.

Now they are able to communicate propperly over the phone and when they are at drop offs and pick ups.  My brother no longer insists his new wife be there for the drop offs and pick ups as he did initially (just to antaganise I am sure) and everyone is a lot happier.

All I can say is that if you take the high road and behave as a model "Person"in their presence (even though it will be an accademy award worthy performance), it will pay off in the end.  You are always going to have to deal with your ex-wife because you share your children.  Eventually you will have school plays, Christmas concerts, sports days, graduations, weddings, births, christenings that you will both (or all 3-4 of you) be wanting to share with your kids and as kids get older it is up to the two of you to make it an easy happy thing or an awkward stresfull (for your child/ren) event.

All you have to be should you encounter your ex's new partner is civil and polite.  A "hi"and a nod is all you need do for now.  Any arangement regarding the kid/s should be dealt betwen you & your ex.  Eventually it may become easier, but that really will depend on you.

I wish you well.