Hello,
Since it appeared immediately after you had sex, so it looks like chafing. Wash the areas several times with fresh water. Do not use any cosmetic products at the sites and do not indulge in intercourse or masturbation for some days. You can apply some calamine lotion at the rash as it will help in soothing the skin. Also wear cotton undergarments. Application of mild corticosteroid cream and oral antiinflammatories like ibuprofen/acetaminophen are also helpful. If the symptoms are severe then it will be best to consult a dermatologist.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
and one more thing it doesnt rly hurt at all as long as im not touching it maybe itches a tiny bit but other then that its painless unless i touch it then it burns like if it was raw skin