My concern comes from the fact that if a punter has oral herpies
Of all the STD/STI's that are out there, Herpes is probably the most over-hyped one there is. It may be highly contageous, and incurable, but as a result statistically, you probably already have it. Something like 2/3rds of the planet have it, and about 90% of American adults have been exposed to it by the time they are 50.
Most people contract the virus when they're kids. You never get rid of it but it lies dormant most of the time. Every now and again people have outbreaks and that's when you can see the sores. A lot of people have less than half a dozen outbreaks in their life. Some times the sores can be tiny, sometimes not so much. Thats the only real time it can be a problem as it leaves you open to catching other infections. Most cases are HSV-1, which is essentially a cold-sore (either on your face or your bits). HSV-2 are a little more severe and have some more complex side effects in very rare cases though.
Ultimately, if you are gonna catch something thats not the one you really have to worry about. Most of the others have significantly more dramatic effects, some can even be fatal if not caught in time, and a lot of them dont have any symptoms in a lot of people until its a problem either. I mean sure you can cure most of them now, but that doesnt mean you want to get gonarhea coated chlamida crabs for shits and giggles.
Ultimately the punting is a risk anyway. How far you push that risk is a judgement call only you can make.