This lump which causes pain on pressure can be due to a swollen lymph node compressing on the nerves, boil or an abscess, sebaceous cyst or a lipoma or hernia. Your husband should apply warm compresses on the lump and take some anti inflammatory pain killer. If the symptoms persist then he should get it checked from a doctor preferably a surgeon. He will do physical examination and if need arises an ultrasound or biopsy of the area.
I hope it helps. Take care and regards.