Wow just wow!
Your mom and your sister don't have your back. They may be your family, but they are not your friends.
You should have just gone to the shower without them.You were being disrespectful to the host of your shower by trying to please (avoid conflict with) your mom and sister.
Stop being the family douche.
You won't ever get from them what you have given. They are threatened by your happiness.
It seems like some kind of passive-agressive behavior is going on here on the part of your sister -- maybe since she was a Bridezilla and enjoyed being the center of attention at her wedding, now she is missing that and is trying to take the attention away from you.
Next time they pull that stunt. I would then just start without them. It is your party and as much as your family wants to control you. This is about you. You are not being a Bridzilla. But they are being FAMILzillas!.
Thiok about it as training for when you have kids. You give them choices. And let them learn from their choices that you will not give in. Next time you have an event important to you. And they decide to go shopping and have lunch instead. And may I point out you were not invited. Then their choice is that Either they get their butts to the event on time or you will go on time without them. And when they try to make their late grand enterance and blame you. Remind them that it was their choice to be late.
There is so many parenting books out there. And it kind of makes me laugh about an episode of Everybody Loves Raymond where Ray and Debra go to a parenting class. And Debra is not as into as she thought and wasn't doing well with the techqniues. And Here comes Ray testing out the theroies on his parents to find out it actually worked on them. (even for a short time)
You like me are a people pleasert and being such we get taken advantage of, Because as someone put it to me, because we don't want to step on anybody's corns. And we just keep quiet. But then it builds up till we blow up. And of course everything is our fault. Even though we know better.
Good luck to you
Thanks for all of the advice guys! I really appreciate it. The uninvited guests were officially "uninvited" and my shower was wonderful! My fiancee's family is awesome and they sure know how to throw a beautiful party.
My mom and sister still make me uneasy about other wedding-related events. They were supposed to get ready with me and drive with me to the shower (it was about 30min away from my apartment). Instead, they didn't contact me until 20min before we were supposed to leave to tell me that they would just meet me at the mall near the hostess's house and then follow me because they deicided to have lunch together and go shopping.
My finacee noticed that this upset me and volunteered to take me to his mom's house so i could ride with his mom and grandma. When we arraived at the mall to get my mom and sister, despite my frequent updates on EXACTLY what time we would get there, they were still shopping and not ready to go. We had to wait in the parking lot while they took their time. the second time I called my mom to try and hurry her, she said "Its not like the party is going to start without you". I was not only hurt, but extremely embarrassed that my future in-laws had to see this side of my family. We ended up 10 min late to the shower instead of half an hour early like I had planned. Thank goodness there was plenty of sangria at the party to get me to relax and be able to truly enjoy my own bridal shower.