Ay doctors what's up with but crack?

I got like a zit looking thing in the middle of my crack and iv popped it a couple times and every time it is a same amount of puss or whatever it is and just basing it off zits on my face they usually go away after you pop them a few times. Could it be something else? I know it isn't some HIV or something cus I don't take it in the bung piece.