get educated on stds and hiv thats your best bet
It would still be zero if one had new piercings or not.
Zilch
Though a new lip piercing or tongue piercing if not healed would up the risk for giving cunninlingus and new tongue piercing for sucking if there is ejaculate
Adding in all risk factors period, high viral load due to new infection the risks are still very low.
I think piercing studios would warn people getting piercings of this.
Piercings may be a higher risk for other STIs, someone more knowlegeable may wish to comment.
I believe it's Zero both ways
what if its the other way around, i.e hiv negative guy giving oral to hiv positive woman?