Those commercials always make me think of the episode of Friends in which Joey ends up in an advertising campaign (or whatever you'd call it) against VD. His picture ends up all over New York, and he can't get anybody to go out with him because of it.
I think that the really rude assumption made in the OP, aside from the erroneous assumption that the mark in question was a cold sore, is that the cold sore was a result of sexual contact. It doesn't matter which type of virus caused it - one should not assume that another person's cold sores are a result of, well, anything. Either type of virus could be passed to the person in question in innocent ways, whether it's HS-1 or HS-2.
As far as I'm concerned, if I had a cold sore (or something that looked like one), the only comment I would find acceptable would be a recommendation for a good medicine to treat it. It's certainly nobody's business how I got the thing in the first place.