Discussions

My friend has been giving me some headaches lately.  
When she sees a guy that is hot she "claims" him basically its stating that only she can flirt him etc.  
There is one guy that she "liked" and asked him out and was rejected.  
 
I recently found out that that guy has a crush on me. I have met him a few times and we talked bout religion and family.  
I never thought about going out with him with but i realized that we are comfortable around each other and have some things in common so now its not out of the question.  
 
Now the problem is my friend found out as well and is mad at me saying that she told me that he was off limits. I replied to her stating these three things:  
 
1. You were rejected by him already  
2. You have a bf right now  
3. He likes me  
 
So she told me if i go out with him our friendship is over...if i dont go out with we can stay friends.  
 
So my question is should i reject him? I really dont want unnecessary drama but i dont think that it is all that fair. Ive been friends with this girl for a bout 4 years, and i have known this guy bout 2 months, me n my friend have different taste in guys so her "Claiming" has never been a problem until now.