At one point, I could never have imagined that a wedding and all its various preparatory activities could potentially make or break friendships, but it happens.
Over the years, I have learned how selfless some people can be: There are the friends who will drop everything and be there for you no matter what. If your car broke down, if a family member passed, if you were having relationship issues -- they were there. Then there is the group who chooses to look the other way and not notice or care if you’re having a bad day. I don’t personally know these people, but I have seen it happen way too often in other people's relationships.
There are people who don’t do something unless there’s something in it for them. But please, be respectful, people! If someone invites you to a bridal shower, bachelorette party or wedding: RSVP. It is not that difficult to say yes or no, and you even don’t need to give a reason, so just respond already. You are obviously important enough to be included, so give an answer.
I have been shocked at how many brides stress about people not sending replies to invitations. I’ve also been shocked at the people who have backed out of an activity at the last minute. It is rude to the bride and the people hosting the function, as well. I would personally be very upset if any of my “close” friends weren’t able to make it to my wedding activities unless they had a legit reason.
So please, be respectful to those who ask you to share in their special occasions.