Seltsame Hautbeule an der Urethra

Hello everyone. I got some weird bump on my urethea. I did have protected sex few times this month, and two days ago this bump just appeared. Second day after sex I felt some pain in there for few seconds and then I saw it. Thing is that it disappears after one day, I get it after I ejaculate. It doesnt hurt or anything, sometimes I can feel some dull pain.

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