on the upper inner part of my thigh, right next to my scrotum but on the thigh. It's under the skin but sore to the touch. i normally shave my crotch and thought it to be an ingrown
by staph aureus and are very painful unless they drain spontaneously or an incision is given by a doctor. Apply warm compresses and Neosporin ointment and avoid messing with it. You can give your father in law anti-inflammatory pain killers like ibuprofen or acetaminophen.
However he may require oral antibiotics and incision and drainage also.
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.