I ve been in a monogamous relationship for almost a year, and my gf and I have unprotected oral and vaginal sex regularly (sometimes anal as well). We entered the relationship clean and have absolutely no reason to suspect any STDs.About 10 days ago I noticed a very small pump about 1mm diameter on the mid-shaft of my penis, white colored under the skin and painless (almost like a white-head zit). The bump started to grow and get redder, with some tenderness developing when the skin was stretched around it but no significant pain or discomfort. 4 days ago the size had stabilized at about approximately 5mm diameter, red in color with smooth skin over top, very minimal discomfort, and I believe it s isolated within the skin (I can feel all around the lesion and under it if I lift up the skin). Starting yesterday, I noticed dry skin over the lesion which started to flake off a little bit, but no significant changes. I haven t tried to pop it nor has it ulcerated at all - is that something I should try to do?My first reaction was maybe HSV, but to me it seems like a pimple, but this is my first time noticing anything odd about my genitals, so pardon my ignorance. I would appreciate any feedback, and thanks in advance!