Thank goodness I'm not the only one! I still feel quite raw over my SIL's behaviour before, during and after the wedding. I also had my other SIL and my half sister as bridesmaids.
I had always thought we got on well despite being quite different personalities, but I was very very wrong and by having her as a bridesmaid, she really did spoil parts of the wedding for me. The main thing that upset me was that she and the other girls didn't wait for me, DM and a friend at the rendezvous even though we had texted to say we were running late, so we ended up waiting and waiting and waiting in the bloody cold for an hour before giving up! In the end it was good fun just the 3 of us!
The atmosphere was so awful in the morning getting ready for the wedding that I actually left the room with DM, DBro and friend. None of them touched the food or drank the champagne DH had arranged to be sent to the room as a surprise. My half sister was having a major sulk that her hair wasn't curling well. It was just awful.
At the wedding reception SIL's boyfriend got so drunk, he started a row about football with my friend who supported a different team to him and made her cry (and believe me she's a very intelligent independent woman!), he smashed a glass during the best mans speech, he smashed another glass on the dance floor, he groped my waist in a really inappropriate way, he tried to take over control of the music. Awful awful awful.
SIL's beef was also undercooked for her tastes so she got up from her table with her plate and showed everyone on my table and asked DH to ask the waiters to send it back to the kitchen. Embarrassing and could have asked a waiter discreetly herself.
I tried to phone SIL after the honeymoon to discuss why I was pissed off but she never answered her phone so I emailed instead and got a snotty email back denying any wrongdoing and also adding that she hates my Mum 
Ideally I would like to never see her again, but unfortunately I don't have that option. I still resent DH for not saying a word about the whole thing either and refusing to admit she was behaving horribly.
Well....totally outed myself there, but quite good to let it all out :o Maybe I need to start my own thread!