Hi ! Good morning. I am Dr Shareef answering your query. From the history, it seems that your boyfriend has got a benign cyst most probably a sebaceous cyst in the scrotal skin. This is not an uncommon occurrence, and though not a dangerous situation, might give rise to recurrent infection of the cyst which may exude pus and foul smelling paste like material at times. If I were his doctor, I would refer him to a general surgeon for a possible excision biopsy of the cyst, which would cure him of the condition. I hope this information would help you in discussing with your family physician/treating doctor in planning your treatment. Thanks for using the health care magic forum for your query on health. Wishing you an early recovery. Dr Shareef.