I don't know if I can help but I have a step-brother and step-sister on my dad's side and they are 1 and 2 years younger than me. I actually went to high school with them so have known them a long time and my dad and step-mum married when i was 18. My step-sister has 2 girls similar in age to mine. They all love each other and see each other as cousins. My step-brother is the problem child We get along ok but don't go out of our way to speak to each other except at family events (actually neither does his sister).

On my mums side I have a step-sister and 2 step-brothers, the same age and a bit younger than me. I went to primary school with them so have also known them for a long time even though my mum and step-father have been married for 10 years. Once again I get along with them all and they have kids similar ages who also treat each other as cousins. I get along best with the middle step-brother, the youngest lives a long way away and he is the black sheep. He and his wife don't visit and we don't really speak to them.

While none of it is nasty I would probably never speak to the ones that i don't get along with again if the step-parent and mine split or one passed away. The others I probably would keep in touch with as we do get along. I find that I just keep things at a pleasant level and don't rock the boat. It's just easier that way.