I can't seem to find anything when I Google, but I am assuming this must be a common problem among blended families where each spouse brings their offspring to the marriage. I have an only child and he used to have just me. Now he has my partner and her two kids close in age as siblings. My son is 9, her son is 8, and her daughter 11. The boys are close yet of course deal with normal sibling issues of fairness and competitiveness. Her kids live with us full time and visit their other mom (yes, there are three moms in this story) on Tuesdays and every other weekend. She is not a person of structure (was not prior to the end of their relationship either) and spends her time with the kids only doing fun things and getting them whatever they want (the Disney Land parent). The problem is that we don't raise the kids like this in our household (over indulgence) and my son feels jealous of course. It is hard to see him in pain, but I don't want to over compensate for the situation at the other house. I don't think that is healthy, not for him, and not for the other kids.
I don't know how to blend when transition is always so hard...when my partner's son is spoiled at the other house and brags about it to my son. I don't know how to fully embrace my partner's kids when these issues keep cropping up and creating rifts in our household. All I want is consistency, love, and kindness, but it seems I don't get to have any control over that. My partner and I are great and have the same goals and values in raising our kids together, and we want to feel unified as a family, but kids are kids. Of course there is sibling rivalry and is natural for the 8 year old to like that he gets to get stuff his brother does not, but it breaks my heart to see the child I brought into the relationship so hurt every other weekend. We tell the 8 year old all of the time to just enjoy his time with his other mom and the importance of not bragging about it, but behind close doors when they are together it still happens. Is there any other solution?