Hi! I do not think that there is anything much of concern about about the symptoms of your husband. This may be a hyper activity of the muscles of the scrotum
. He does not have any pain, or redness
, and so we can exclude any infective pathology. However, he should use proper scrotal support garments whenever he lifts weights and does any kind of strenous work. A proper re assurance will help him. If the symptoms persist or increases with any other problem, he should consult the family physician for a routine check up. Hope this helps your husband.