<human>: So my brother, let's call him Josh,  is marrying his girlfriend of 4 years who we will call Megan. It is the first real relationship that they have both been in. Josh had a few girlfriends before Megan, but Megan has never dated anyone but Josh. 

At the beginning of their relationship they were great, and she was super easy to get along with. She was seen as his saving grace, he had mild depression before they met. 

But within the past year after they got engaged, everything has started to go down hill. She is extremely controlling of him, everything that he does has to be approved by her first. She manipulates him to the point where he doesn't even have an opinion anymore. She is very immature, always pouting and whining when she doesn't get her way.

They constantly yell and argue,  Calling each other inappropriate names and having screaming matches.
My whole family has sat down and talked to him, we have all expressed our dislike for her, and the way she treats him.
Yet he is always quick to defend her even though he clearly is unhappy. It had gotten to the point where the family is divided between people who can be around Megan, and everyone else who can not. 

I feel like she is going to be the reason that my brother and I don't stay as close as we have always been. He is my best friend and I hate seeing him go through this. I fear he won't realize he is making a big mistake until it is too late.

Can you give me the gist of the text in a nutshell?
<bot>: My brother is marrying a terrible woman who my entire family absolutely hates. I fear this won't end well and it will destroy him.