Hi, dear I have gone through your question. I can understand your concern. He has pain on touch in inguinal lymph node. It is acute and he may have some infection in urethra. So overall history suggest it may be reactive lymph node. You should a course of antibiotics. If it remains persistent then biopsy diagnosis is advisable. Consult your doctor and plan accordingly. Hope I have answered your question. if you have any doubts then feel free to ask me. I will be happy to answer. Thanks for using health care magic. Wish you a very good health.