My husband complains of his tentacles hurting. he had a vasectomy & a reversal so we could have a baby. what could cause this?

Depends: Depends on how long ago surgery was. If it was recent, it would be expected. Use ice, support and ibuprofen. If its been years i'd do the same but get checked out. Could be trauma, hernia, infection, a fluid collection or rarely cancer.

Complicated: Occasionally, one will have post vasectomy vaso-congestion. This usually resolves and all is well. However, after a "re-do" vasectomy or a reversal, this can happen perhaps more significantly. The small lymphatic channels are disrupted, small nerves are injured, scarring develops, small vessels are interrupted and a whole scenario develops that can cause pain, swelling, discomfort and such.