I Looked Up In A Quick Anatomy Page. The Urinary

I looked up in a quick anatomy page. The urinary meatus or tip of my penis where urine and semen come out is getting bigger. When I was a stupid kid around 8 I put something in and it opened a little bit larger than it was. I'm 34 now and have had multiple partners thru my life with protection most of the time. However this past week it has gotten even larger without any sexual activity. Urine flows thru fine until the very end when there is less pressure, it goes everywhere. What is going on? I just started a relationship so we both had ourselves tested for std's. I was given a clean bill of health.