no personal experience with this but any time any of the snakes I've been handling or maintaining habitats for start oozing liquids out of places they shouldn't it means a trip to the vet. Most likely it will need some sort of reptile-friendly antibiotic if you want it to live. It's obviously infected.

Don't do anything until Mike posts in here though

Learn your lesson about keeping snakes together? I'm sure lots of people have been through similar experiences for very similar reasons and it's a harsh way to learn that some species don't play well with others or even their own species.

Good luck!