The 26-year-old bride wrote that she and her fiancé, 28, have been engaged for four months and their wedding is set for October 18.
"[She] said that she knew better and tried to get me to approve of wedding dresses that she chose and when she couldn't enforce her decision she demanded that I take her with me to buy my wedding dress so she could have an opinion," the bride-to-be wrote.
"Before I went shopping I called her to ask if she wanted to come but started making excuses about how busy she was with my sister in law, I went shopping with my mom and I was able to find a really nice dress although it cost me a little over what I saved up for, but it was worth it."
"I made some changes to it and it was perfect,” she went on, “it arrived to my apartment at the end of the week, I made sure it was stored in a safe place so it doesn't get ruined."
However, she got home one day to find her fiancé wasn't there and neither was her dress.
"I called him immediately knowing that he must've taken it to show it to his mom since she continuously asked to see it and refused to have me send her pictures of it on Facebook."
It was quickly confirmed that her worst nightmare was true – her dress has been taken to her mother-in-law's house. But it gets worse.
"He said he was gonna be home in 30 minutes after he went to the supermarket I waited for longer than I had to and then when he arrived I ran to get my dress that was buried underneath grocery bags,” she wrote.
“I took it to check on it and it's zipper was broken and the dress itself (fabric) was stretched out, I was like what the f*** happened to it, my mother in law must've tried it on, because it looked ruined, the straps were almost loose, I had to call my mother in law when my fiancé told me his mom and sister took turns to try it on, I was absolutely livid, she told me she did nothing wrong and that I was making a big deal out of it."
When asked to pay for a new dress, the mother-in-law refused.
"She said she'd get a replacement for the broken zipper, but I told her to pay for a new dress since it was stretched out and no longer fitting,” the bride explained.
“She refused and said that I probably wasn't happy with my dress choice and wanted to her to pay so I could get a new one, I yelled at her for trying it on and ruining it, that she and my fiancé were responsible for ruining my dress so they should pay for a new one.
“It's done, no longer fitting, the straps are in a horrible condition, my mom said she'd pay for fixing it but I just hate it now that someone else wore it before me."
She finished by saying she was upset with both of them and is "seriously considering postponing the wedding".
The bride questioned whether she was “the a**hole” for demanding her future husband and mother-in-law pay for a new wedding dress – and Reddit users did not hold back with their feedback.
"NTA. Girl do you hear yourself?? Your fiance took your wedding dress without permission and allowed multiple people to try it on!" one user wrote.
"Do you understand how disrespectful and inappropriate that is? You not only have a bad mother in law problem, you have a HUGE fiancé problem.
“Needless to say, I'd be doing more than postponing."
"[You] not only have a bad mother in law problem, you have a HUGE fiancé problem," another said.
"I find it revolting that his mother and sister would even want to wear DIL's wedding dress," someone else wrote.
Another agreed, "You don’t need a new dress you need a new fiancé. NTA."
Many also said that the poster would "always be second best to his mother and sister".
"Get the money for the ruined dress THEN break your engagement and break up with him,” one user wrote.
"You're lucky he showed you where his true loyalties lied before the wedding. Divorces are time consuming and expensive."