Thanks for your query.Based on the facts that you have posted it appears that your boyfriend has developed multiple sebaceous cysts over scrotum
The scrotal skin is rich in sebaceous glands compared to skin of the rest of the body ,hence it is prone to develop sebaceous cysts which occurs due to accumulation of sebum beneath the skin. Normally no treatment is required as these cyst fade away of their own. However you need to take antibiotic if they get infected or need to get excised if increase in size. Observe proper personal hygiene. Please consult quakified surgeon or Dermatologist
for clinical examination and further treatment.