AITA for not letting my brother stay in the apartment I paid for since I’m not living there anymore?

I’m 22F, I will start studying this fall and need an apartment to live in. To avoid the hassle of searching for another roommate or dealing with a short-term lease, I saved up money for years and spent it on a student apartment. To avoid paying rent I promised to move from both parents and in-laws house to there as soon as I got my acceptance letter and to move back in with my parents after I graduated. To summarize I put “money” on the apartment, I paid it “beforehand” in years of my freedom. I was lucky enough to get in a uni where most of its students live in the dorms so I didn’t have to pay much. Being an early bird, I moved in “exactly when I was supposed to” in order to study hard before uni starts, I’m studying “medicine” if you must know.<br><br>At the end of last month my brother asked me if he could stay in my apartment “before anyone else does”, he was asking because my brother’s friend “B” was in trouble; I’m sure you’ve heard it before, his parents decided to flip his room and make it a home gym “for both of them” so he has no place to stay there, and now that I’m moving “before time” the room is now apparently empty and he asked “nicely”. I’m not a heartless person so I said yes, my uni hasn’t started yet and everything is closed anyway so I’ll have a little fun. Being an early bird, I moved exactly a week after I said yes. <br><br>And here is the problem; my brother was mad abt my answer and thought that I was joking, I wasn’t. When I moved in a week ago, he was mad, asked me “wtf am I doing” and I said I’m starting to live there, he laughed at first and said okay “B” will stay until I move in “for real”. I told him that I moved in now and I’m not moving back, and since we lived with mom and dad, his room is not touched and nothing happened to it so his friend can’t stay there. He laughed again and said okay “B” will stay there until I move in “for real” again, I said I moved “for real” and it’s not up to him to decide and that “B” can’t stay there anymore, he got mad at me and told me that I had no “heart” and that I shouldn’t play with others “feelings like that” and I’m letting him down and I “owe” him this one since he’s my big brother and I said okay fine “B” can stay there, he asked for how long and I said “until I move in” and he said what he said before, we went in circles and I got mad and said “for as long as I want to” and since it’s my place and I paid for it, “B” will leave “for real” now, he was mad and I’m mad too and since I’m there I “won” and my brother told me that this is not right and I’m hurting him and letting him down and that he will stay there “for as long as he wants” and if I want him to leave then I should stay with mom and dad until he leaves and I had enough and asked him to either leave or call the police because what he’s doing is both trespassing and harassment. He called the police and guess what, “B” was asked to leave and my brother was mad.<br><br>Now my brother is angry at me and told me that what I’m doing “is not right” and I’m letting him down and hurting him, my parents are mad at me for not letting “B” stay but they’re on my side and told me that what I did was “right” now I’m living there but my brother is angry at me and asked me to stay with mom and dad until “B” stays there now and said what I’m doing “is not right” and I’m hurting him, my friends are divided, half of them said I shouldn’t have kicked him out and I did what was “right” and the other half said that I need to let him stay and that what I did was “wrong”.