wedding debate

So two of my very good friends are getting married on the same day and I don't know which wedding to go to. I have to mail in the RSVP really soon (like yesterday). One girl, Leigh, I have known my entire life. This is not an exaggeration, she was at my baby shower before I was born because she is a few months older than me. But we haven't been that close lately and I don't know her fiance. However, if I went to her wedding I could also see my grandparents and maybe even go to the beach for a few hours. The other wedding is for Mary Louise, the girl that was president of Zeta when I was rush chair. We have been through a lot and have been good friends in college. Also, a lot of my sorority sisters will be at that wedding and I could see all my Houston friends. So what do I do? How do I pick? And when did I get to be so bad at making decisions??