weird rash to have no pain or itching. is the skin real dry? could you have been damp for too long causing it to break out? doesnt look like a std.i see it kind of goes into your hole, is it inside as well? any bumps?
it look absoltly normal to me, a little dry skin maybe. try some mild unscented moisturiser down there for a week or so, see if any changes. doesnt look like Lichen Sclerosus
looks like dermatitis nothing serious.