For many people, hanging out with extended family can be a bit of a drag. You don’t need to have a real problem with your dad’s second wife and her kids to not want to spend a lot of time with them, especially if he hasn’t made much of an effort to spend time with you. Many parents think that because they have kids, random family members will suddenly become highly invested in spending time with them and their kids. While that does happen in many families (if you’ve been to a family Christmas without any childlike wonder, you know it can get quite bleak), having kids doesn’t make your nuclear family a priority for estranged family members. Estranged children from previous marriages might feel kind of resentful for being expected to make an effort in a family that only exists because their parent quit their first nuclear family.