Your outbreak could be herpes zoster or HSV. The only thing that herpes means is that the virus lives on the nerve root in a latency phase and then outbreaks periodically. Varicella zoster is colloquially known as chicken pox and herpes zoster is when the virus recurs and is known as shingles. Either can occur within the buttock region. The reason your doctor told you that it doesn't make a difference which one it is is because the treatment options are mostly the same so the course of treatment wouldn't change regardless of the outcome. However, WCSDancer is correct in that preventative measures could be used for your partner if you do in fact have HSV. In your case, I would recommend testing for HSV antibodies for both you and your partner. If the test returns negative for both, then HSV is pretty much ruled out as long as it is true that both parties have not participated in any extra-marital affairs. Either way, there are many treatment options that can be used to help treat the pain other than anti-viral medications. You can also receive a shingles vaccine which may help future outbreaks. In my opinion, your symptoms are more consistent with Herpes zoster and not HSV.