As some background, I go to a co-ed boarding high school. I have a girlfriend back home and am straight. My wing in the dorms is filled with a large collection of my friends. We're close- we play basketball, guitar, tennis, and poker together whenever we have free time.
We're all straight except for one bisexual friend, whom I'll code name Bob. We completely accept and support his sexuality. Bob is quite emotional, and has talked individually to each of us about his social anxiety and coming out to a select group of people as bisexual. In his talk, he has mentioned to us (individually) that he's depressed because he has an intense crush on another male at our school, who he doesn't name (to me), has a girlfriend, is completely straight, and understands that there's no chance that he would ever be in a relationship with.
The rest of us friends have talked about it, in private, to confirm that I'm the only one that has heard the talk about the anonymous person he has a crush on three times. He's offered to tell another one of us who his crush is, yet this individual honestly declined the information (wisely, but it doesn't really help me). This leads me to think that he's specifically attracted to me.
As friends, we hate to see his obvious sorrow about this impossible relationship. However, in the case that this is possibly directed toward me (and I'm very sure this is the case), I feel like I have to do something for him to get over me as a crush, while still keeping him as a friend.
What can I do to help Bob get over me as a crush while still keeping him as a friend?
Note: We're Americans east of the Mississippi.
I've looked at related questions (Reject a close friend interested in dating me? and How can I help a close friend get over me?), but the difference here is that I'm not 100% sure that his crush is directed toward me.
Bob has specified that he has had this crush for several months.