Okay so here is the story:

I met this guy a couple of month a ago. We are like hanging out all the time but we decided to be good friends. We meet up nearly every day, drink coffee or study or go partying etc.
So I met his flat mates at there party and there where all asking me if we have something going on or not... I answered no (logically because there was nothing)
And they kept on telling me how awesome he is and blablabla.

So after this party I started thinking about it and I must admit I actually kind of fall for him. I have been struggeling for over a week now and I still fancy him.
So we went out again - I kissed an other boy- and in the morning when my friend got home he texted me: did you arrive safe home? With or without the guy?
So that confused me even more.
The next day I see him and he was acting kind of weird, didn't get up to say hello, didn't hug me or didn't look in my eyes as he usually does. So please help me...

Like we are so good friends and I really don't want to destroy it but how can I get over it?

You're confusing me now. You say you fell for him but at the end you say you want to get over him? Which is it?

I'd say he was acting weird because maybe he's jealous. I think he didn't like the fact that you kissed that other guy because he has feelings for you too. Do you know how hard it is to have a friendship with the opposite sex without one falling for the other? It's not uncommon, it's just unlikely.