application for a Parental Responsibility Order is a relatively straightforward application.   It is important to have parental responsibility as not only does it give you the right to be consulted on all important matters regarding the children, but if something were to happen to the children's mother and she has appointed for example a new husband or another relative as guardian of the children in her Will, then that appointment would be effective as you would not have parental responsibility. Bearing in mind your involvement with the children's lives and your regular contact, I do believe that the Court would make a Parental Responsibility Order in your favour.   I can see no reason as to why your former partner would not agree to enter in a Parental Responsibility Agreement with you.   If she is agreeable, then you can obtain the Parental Responsibility Agreement form online or at your Local County Court. Before you make an application to Court for a Parental Responsibility Order, you should invite your ex partner to go to mediation with you to see if this issue could be resolved at mediation. Your ex partner's remarriage would not automatically give her new husband parental responsibility of the children.  He would have to make an application to Court for parental responsibility and you would be served notice of that application. My fiance just had a new parenting plan put into plae for her daughter.. now the father of her son is the second respondant on this new plan.