My husband has an older child from his previous relationship and we share Dc too.
I met DSC when they were 5 and they are now 11. Our DC is a toddler.
Basically my family has never hugely been involved with DSC. They are nice when they see them but they don't go out of their way to see / talk about them etc... They get a token gift for Christmas from a couple of members of my family and my parents chuck a tenner in a card for their birthdays that sort of thing. I've always thought this was fine, they aren't their grandkids / nephew at the end of the day. Admittedly our son is spoilt a lot by my family but again, always thought that was fine and fair enough.
Anyway, he's made little comments in the past but basically my sister has asked if she can take our toddler with her and her husband and their DC to their holiday home during the summer as they also have a young child and our DC gets on well with them. We can't afford a holiday this year so thought it was great for our DC and was very grateful.
Anyway, my husband has now let all of this out that he thinks my family should make more effort with their 'stepgrandchild/nephew' and it's been bugging him for a while and I should speak to them about it. He seems pissed that I'm not pissed about it. I think they are entirely reasonable and it's their right and choice how involved they wish to be.
My sister does also have another DC similar age to DSC so he thinks why couldn't DSS go too and has said he'll pay if that's the issue. But his wider issue just seems to be around the fact the DC aren't treated the same.
AIBU to think he's being ridiculous and to say there's no way I'm bringing this up with my family and making out like they are doing something wrong.