These could be anatomical lumps. There is a tube situated on both testicles, it is called epidydimis, it ranges from top to the bottom. It is 5 meters long and curled up, so bumps may be felt when touching thoroughly.

On top of the testicles, spermatocele could form but what are the odds that he would get two on the same place on both testicles (although spermatocele do usually form on top of epidydimis).