'AITA for choosing to go to my best friend’s wedding over my sister's?'

"AITA for choosing to go to my best friend’s wedding over my sister's?"

9 months ago my girlfriend and I were asked to stand in my best friend’s wedding as bridesmaid and groomsmen. We accepted the offer to stand in the wedding and have been involved in planning of the bachelor/bachelorette trips and the wedding itself. My friend’s wedding is already booked for next September 26th with a deposit down and the date cannot be changed.

Recently my sister got engaged, about 3 weeks ago, and has started planning her wedding. She originally had chosen a date in October of next year but had to change it due to someone booking that date. My sister told my girlfriend and I that she was changing the date to September 26th as that was the only other date the venue had available at the time.

I told my sister we would not be able to make it as we had committed to my friend’s wedding 9 months ago and they had already booked a venue and it was too late to change anything.

My sister got upset and told us that we could just cancel on them and that they should understand since she is my blood relative and my only sister and argued that she was more important than a friend from high school. We told her that we would not cancel on them and she would have to pick another date or accept that we wouldn’t be there.

2 days later knowing this information my sister booked her wedding venue for the same night as my friends wedding and continued to be upset with my girlfriend and I.

My sister thinks I’m the bad guy for choosing my friend over her. I think my sister is the bad guy since she was the only one capable of changing the date and resolving the issue, but instead chose the same date and is forcing me to be the bad guy and choose between them. AITAH?

This is what people had to say to OP:

Persis- said:

“What kind of man would I be to back out of a commitment? I will be sad to miss your wedding, but you were aware of my schedule conflict, so this is what YOU chose.”

catlettuce said:

NTA. It appears your sister might be too immature to be committing to marriage, but that's her spouse to be's problem.

janus1981 said:

NTA. But your sister is doing this deliberately for some reason. You should find out what it is.

Buho45 said:

Integrity=doing the right thing even though there may be negative consequences for you.

OP later shared this edit in response to comments:

To answer a few questions yall have been asking, the only other date available was in December but she claimed “she didn’t want to get married in the cold."

My entire family as well as my friend is aware of the situation and they have all agreed with me in my decision to attend my friend’s wedding as it was a prior commitment. My sister and her fiance have been together for about 4-5 years and have a kid together so he knows fully what he’s getting in to.