I get that you would feel that way - I felt a similar way when I found out my sister was doing all these different things with my siblings (blood and in law) but not me, but when I asked her about it (very gently of course - not confronting) it was just a combination of absolute oblivion to my sense of exclusion, and a general impression that I was always busy, and would have been too busy for catch ups with her.

So I've started inviting her to stuff on a very ad hoc basis (a meal here, a trip to the park with the kids there) and she's really leapt at the opportunities 99% of the time, which has been really nice.

That being said, while typing that out it occurs to me now that I haven't done that with my brothers or their wives, so hopefully they're now not thinking that DH and I do all this stuff with my folks and my sister, and leave them out ...

Maybe they think (correctly or incorrectly) that you're not as into the activity as them, or maybe they really cherish that 1-on-1 time or maybe they just assume you'd ask if you wanted to come more often ...

If you're keen to join in more, I'd say so Tell them that you really love hanging out and crafting it up, and say that you'd like to come more often (once a month, every time, whatever) but express that you appreciate that they're close and you don't want to overstep ... and I'd sort of put it back on them a bit - that you don't need an answer then and there, but if they could have a think and let you know, that would be great. I think most people would take that seriously - that you're voicing your feelings, that you like them and want to spend time, but that you respect their feelings and preferences too, and nobody, *nobody* wants to feel like the fly in the ointment, so an honest response would be appreciated.

Besides, if the relationship is one that you enjoy and appreciate and want to commit more time to, then one would hope they'll be respectful and honest in responding

Have a think, and good luck.