I am really good at remembering my siblings partners & children's birthdays. One sibling remembers my children's b'days, other one is hit & miss.
Both of them forget my DH bday, in fact one of them has never ever sent a card & the other one may remember a few weeks later and he gets a belated card. We're all adults however this really upsets and bugs me that quite frankly they aren't bothered.
So, I would find it hard to not give their children cards / gifts on time.
Would it be churlish of me to stop acknowledging their partners birthdays as they do to my DH? Two wrongs don't make a right and all that?