This may come off stupid or uneducated, but it is a concern. A week ago, over a a friends house, I was waiting for my pants to dry and was straddling her thigh wearing nothing but a small pair of thong panties. They don't really cover very well as most know. She had an itchy spot on her thigh but was just diagnosed that it was not an allergic reaction, but HSV-2. Because I was sitting there, with little to no coverage, is it possible for me to be infected?
That's not a stupid question at all given the unique situation.
If the infected site on her thigh (to my understanding of your post, the itchy spot on her thigh was evidence of the HSV-2 infection, right?) came into contact with any of your mucous membranes in some manner (direct, hand to infection to mucous membrane) - genital region, oral, eyes, etc, it is possible for the virus to be transmitted.
If it is directly skin to skin with no mucous membranes or breaks in the skin (like a cut, scrape, etc), it is fine which is why public toilet seats and the like are mostly safe when it comes to STIs.
If you have concerns over this, a blood test within - I forget how many months - can be taken by your doctor to test for the virus.
All the best!