I have three children but one is an adult and doesn't live at him. At home I have a 16 year old son, an 11 year old daughter and a 5 year old granddaughter. My fiancé has twin boys. We've been together a year and a half and haven't had much trouble with our kids getting on together. His kids are only 15 months and they've been coming to us since a few months old so everyone seems to be getting used to each other. It's when it comes to our extended family on my fiance's side that there may be more issues. But My kids already consider his kids their little brothers.