21-year-old brother refuses to let 27-year-old sister take over his apartment after her breakup, parents side with the sister: '[Am I wrong] for saying no?'

This dude just saved enough money to rent his first 1-bedroom apartment. The last thing he wanted now was for his older sister to move in with him.

Unfortunately for this author, that is the predicament in which he has found himself. At 21, he was looking forward to the experience of having his own space and finally getting to live on his own terms. He also had earned it. He saved the money from working jobs while being a college student in order to afford his own place. Sure, he is only 21, and most people his age are used to crashing on one another's couches and sharing small apartments because they cannot afford the luxury of personal space. Still, this guy was already tired of that life, and he worked his way to be able to hopefully never have to do it again.

This all happened before his older sister, who is 28, broke up with her boyfriend. She had moved back in with their parents and was not handling this transition well at all. She asked her younger brother if she could move into his place for an indefinite amount of time. The author probably would have said yes if it had been a night or two or maybe even a week. However, the fact that she demanded that he agree to letting her take over his new space without any specification as to how long it would take for her to get back on her feet was a red flag. 

After all, the sister is seven years older than the author and should be able to, at the very least, understand and respect the author's boundaries. Instead, she couldn't see his perspective. In fact, she even went so far as to suggest that she stay in his place solo while he went back to live with her parents. Her justification was that she was the person who needed her own space at this time. That may be true, but if she wants to live alone, she is going to have to pay for that arrangement herself.