What Causes Sudden Appearance Of Open Sores In Buttock Cracks?

My boyfriend has had this occur in the past and all of a sudden it came out of nowhere again..At the very top of his butt crack he has these 2 open pores and another one about to open. They're about the size where you can stick the tip of a pencil in it(a little bigger though) the one on top...hair comes out and the one below is nothing but pus. He doesnt have the money to go to the doctors so what should he do?