What is this bump with a hole on my scrotum? (photos)

Background: I received oral sex on Wednesday. I have had a couple of ingrown hairs in the past, but no STDs.

-On Friday I noticed one medium sized pinkish bump on my scrotum, near where it meets the leg.
-On Saturday it had a bit of white pus, looked somewhat like a pimple, a small dark dot also seemed to be visible near the center.
-On Sunday it filled with quite a bit of white pus.
-On Monday morning almost all of the white is gone, and there's a hole in the center of the bump.

Here are photos from each day - I have read and read and can't tell what on earth it is for sure.
http://img4.imageshack.us/gal.php?g=img9136w.jpg

looks like your every day average ingrown hair with a pimple. After the pimple popped(drained) the space where the hair and fluid was looks like a hole. It will heal just like a cut or wound and be gone in a week. Put some neosporin on it a couple times a day and in general try to exfoliate daily any area on your body that is prone to ingrown hairs and/or pimples. You're normal buddy!