How do I not make this awkward?

[Gusteau]

OK, first of all, you're rush did not have the "worst possible outcome" because you got a bid somewhere.

Depending on campus culture, I don't think it would be awkward to call up the third fraternity. Your post leads me to believe that the groups on your campus are conducting a dynamic continuous recruitment where they are constantly meeting people and recruiting them (and by recruiting I mean becoming friends with them, not handing out bids year round). If they are recruiting like this, I wouldn't be surprised if they contacted you to grab lunch soon. However, things do get very busy with a new pledge class and some chapter members forget that recruitment does not end, so if it's what you really want I don't see any reason not to take matters into your own hands.

I would also recommend that you go to the second fraternity's chapter meeting. I only knew a few of the brothers going into rush, and for some reason I did not think I would get along with the ones I did not already know. This turned out to be a completely untrue snap judgment. I am very close with a lot of those guys who I originally thought I wouldn't want to hang out with.

I don't think you should feel guilty for choosing a fraternity that is right for you, but I do think you will feel guilty for not giving #2 a fair chance.

[MMSe]

Thanks Gusteau, that's good advice.
When I ate lunch with the vice president, he did say that the fraternity has "unofficial recruitment", which is where, he said, they are always on the lookout for new members and for recruiting guys even after "official" rush ends. So that does make me feel better about calling them up, especially because one of the guys I liked talking to was the recruitment chair.

And after I met with my friend who is the rush chair for my original backup and explained all of this to him, I chose to defer on their bid. I told him straight up that I was still considering joining another fraternity, but he seemed to indicate that was okay. So I have a week to change my "defer' to "accept" for this one, but it seems like this semester I can just hang out with both groups and see which one I fit in better with.