I've never had an easy relationship with my inlaws and there have been several big rows with them over the years. Today is our 9th Wedding Anniversary, and as expected there wasn't a card from them. We used to get them but following a huge row 5 years ago the cards stopped. It's not like they forget, they'll wish a Happy Anniversary to DH on the phone.
I know I should be used to it after 5 years but it still really, really hurts.