One or both parents may decide to re-marry or to live with a new partner after a divorce or other parental relationship dissolution has taken place. Plans for parental remarriage can trigger a new difficult transition for children who now have to accommodate not only the loss of their original nuclear family, but also the introduction of new and alien "step" parents and siblings, possibly a move to a new house, and other related shakeups that turn children's world upside down again. There is no real way to shield children from the need to adjust to these changes. What parents can do to make the transition easier for children to manage is to talk with them about it, discussing how life might change after the remarriage, and encouraging them to ask questions and share their feelings about the changes.
When blending a family, it's important for step-parents to understand that while they may be able to eventually develop a positive relationship with their new step-children, this process cannot be forced or rushed. It's natural for children to feel loyal to their original parents and to worry what their "first" parents will feel or think if they warm up to step-parents. The development of positive feelings towards a step parent may cause a great degree of internal conflict within children who worry that they are disloyal. Step-parents are advised to explain to children up front that they do not want or intend to replace their original parents. Instead, step-children should be told that the new relationship will be different then the one they have with their original parents. The step parent is not a substitute parent; he or she will function more like an additional parent (albeit, a limited kind of parent).
Step-parents should not be expected to enforce discipline with their step-children. This can seem like a difficult goal to meet in today's busy society when it is likely that children's primary parent will be out of the house working when discipline needs to occur. However, it's important that step-parents are not placed in the direct disciplinarian role, precisely because that role needs to be occupied by someone children fundamentally trust, and step-parents may not be fully trusted by step-children for many years, if ever. Rather than forcing the discipline situation into a shape it doesn't naturally want to fit, families are better off presenting step-parents the adults in charge when the original parents are not at home, much like the babysitter or Grandma. Step-parents can guide the general routine of the day, such as encouraging homework, bath time and chores, but overall, enforcing rules and consequences should be left to the children's original parents unless children get into an immediately dangerous situation that requires immediate adult intervention.
For example, if Johnny's mom has to work late one night, Johnny's step-dad can help remind him to do his homework and take his bath before bed. It's wonderful if Johnny complies and does these things as asked. However, if Johnny begins to argue or to refuse these requests, his step-dad should refrain from using a negative consequence or entering into a power struggle with Johnny so as to force the issue. Instead, Johnny's step-dad should allow him to go to bed without completing the tasks, and allow his mom to handle the discipline lapse the following day. Johnny's mom should be the one to decide and enforce the consequences for Johnny's inappropriate behavior.
If Mom routinely has to work late and Johnny continues to avoid completing tasks, Johnny, Mom, and Step-Dad can sit down together and discuss what will happen in those situations, with Mom guiding the conference and making the rules. If Johnny continues to act out and refuse to comply with Mom's requests as transmitted through Step-Dad, it may be a sign that he's missing his mother's presence, attention, and affection and is asking her to be more involved in his life through this behavior. Mom may need to figure out additional ways to communicate her love and support for her son.