This looks like it may be a fungal infection of the skin. I would recommend you see a urologist for an exam to see if you should be started on a medication such as betamethasone with Clotrimazole to clear the inflammation or fungal infection. Hope this helps.
It would be best to get this treated first. You can have protected sex with a condom until you are seen by a urologist to prescribe this.
Without being able to do formal testing on the area, I can't be sure that this is a fungal infection or not. But it really does not look like anything else. It could just be an early fungal infection. In this type of scenario, it is calm and just to treat this as a fungal infection with medication designed to treat A fungal infection to see if it responds. Hope this helps and please don't forget to leave me a rating. Thanks.
It can be from diabetes, being uncircumcised, or it can happen from no reason at all. It is not from being dirty.