<human>: I have a had a crush on my best friends roommate and I have talked to her occasionally since I hang out with her roommate all the time. Her roommate is gone and I have been spending all my time with her for the last week. We both can't help but smile when we make eye contact and she acts really bashful when she talks to me. 

Cut to last night: She insists I go to a party with her, and I was pretty pumped. We get there and she immediately introduces me to her best friend[21F] that my friends have just referred to as the Sasha Grey look alike. My crush starts dancing with a random guy and her friend tries to dance with me, but I decline since it would not be a good idea to show interest in my crush's best friend and I "left to find my friends" (I just went for a walk and told my friend about my predicament).

We get back and my crush and her friend got mad at me for leaving them and we went for some late night food. My crush's friend then continues to flirt with me and invites me to her house. I declined again and she invited me to come over and drink with her on Friday. I told her that I would if my crush is coming.

I asked my crush to dinner today, and she said that she had to work, so it wouldnt work. I then asked her about tomorrow and she said that she might be visiting her family, but if not, then she would. Now she is going to see her family. I have to ask her out before next Sunday if I ever want to date her, because my roommate is gone until then and he will stop at no length to keep me from dating one of his friends.

Her best friend is gorgeous, but so is my crush and she is one of the most kind hearted, funny people I know.

Should I ask her to dinner again some time this week and tell her how I feel, or should I give up and move on? If she says no, is it safe to date her friend?

Can you condense the text into a few key points?
<bot>: I have to ask my crush out within a week or else it wont happen and I don't know if she is interested in me. What should I do?