To not invite people to an event again after they didn't give an answer until the day of with no excuse?

Long story short OH cousins weren't supportive during most of our relationship (not married), ditched day of baby shower and are now expecting to be invited to close family wedding of ours.

They refused to give an answer until the day of because they couldn't fake being supportive.

I just don't want that type of people in our lives. Especially not at happy occasions.