It does not sound like epididymitus at all, which would cause pain and fever.
He needs to see a urologist.
This is not a self diagnosis situation.
He probably needs an ultrasound of the testicle.
He also needs an assessment of his lower spine to make sure he does not have nerve compression.
There are nerves that would cause this symptom in thigh and testing.
The problem can resolve, but there still can be disc problems in the spine that can cause problems later.
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