Hi young man. Thanks for your query. Good description of your problem and the sign of grown-up boy ( not telling the parents ). Well, this is due to the fact that you are growing up has caused changes , the skin of the scrotum can too show these the way you have described . These are small multiple sebaceous cysts and nothing to worry. Please consult a Dermatologist and he would tell whether you need a treatment for this. Keep the area clean with washing it as many time as possible with plain water and keep the area dry and well ventilated. No tight underwear or pants.