Help/advice Wanted (The Great Roommate Dilemna)

Let me start with some background information, she and I are both college students and we lived in the dorms very close to each other. She is a little older than I am, but age is but a number to both of us. We developed a friendship and once college ended, we were seperated for two weeks and that’s when it really sunk in that I missed her. When she came back to school, I picked her up from the airport and we went back to the house we and one friend are now renting. That week she and I slept together because we only had one bed.

However, one of my best friends also started falling for and that’s where the problem begins. He and I had been friends for 4 years until he went to college. But now that we are both at the same college, we are starting to hang out again a little but he is reallly into her. My dilemna is, do I go for the girl that I have so many things in common with and so many feelings for and possibly lose my old friend, or do I stay loyal to the friend and certainly lose the girl and see her get hurt (I can knowingly say they would not last..)