Spirit Follows Me?

I don't really see myself as sensitive towards spirits but I've had this one follow me for some time and I'd like to know why or if it means me harm.

It started when I moved in with my aunt and uncle, roughly a year ago. I always felt somebody watching me but assumed at first it was the new environment.

Then it would start to watch me get dressed and gasp at me, I would hear the bathroom door trying to open whilst I showered and there was the one corner in my bedroom where I would feel it staring at me.

I literally have weeks where I won't hear anything off of it, then there will be nights where I'll feel it staring at me and sometimes it would call me a "slut," whisper in my ear or smack me to wake me up. I don't understand why it has never really "hurt" me but it insists on living in my room?

Although there have been a few occasions where I've stayed at family or friends' houses and they've claimed to have unexplained things happen to them such as doors slamming, or hearing somebody walking in heavy boots.

To be honest, I had nearly forgotten about it until my friend came over, and she said whenever she was sat in my bedroom or bathroom she would see it watching her from the doorway but whenever she tried to look it would run away. She described it as a man about 6"4, in a black suit and hardly any visible facial features, exactly the same as I'd imagined him to look!

So I was wondering, is this thing dangerous? Why does it harass people I am close to and do I need to tell it to go away?