The problem with self diagnosing is oftentimes it's wrong. You have a draining lesion - you need to go be seen and get it checked out. With the incidence of MRSA related skin issues out there you don't want to put this off. It's not likely to be a std.
grace
it could be a absess. they drain like that and i get them sometimes around that area too. Im not too sure what their from but if you get them to drain all the **** out of it, then it should clear up and go away within 2 weeks. Only a guess!