hair follicle, oil glands, lympohocoel, Fordyce spots, sebaceous cyst, sexually transmitted diseases etc. Maintain good genital hygiene by cleaning with soap and water, don’t try to squeeze the pimple. Applying ice would reduce redness, pain or swelling. See a dermatologist if problem persists for more than 1-2 weeks.
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.