spots or pimples have developed on my scrotums?

Hello sir i am married guy. There are six or seven spots or pimples have developed all over of my scrotums from two years,its looks like black channa and hard, there is no pain when i press hardly into my finder but very itches in the night,I have sex so many time with call girls but always do safe sex, I ask many of my friends about this , they always said to check this, its could be symptoms of a bad disease, i'm quite worried, can someone please help me?