The risk is very low. Its not zero risk but the odds are very much in the favor of him not being inflected.
2 days. Average is 4-5 days.
Do you have hsv1 or hsv2?
Can symptoms appear within 12hrs of infection?
Ok. Being on antiviral meds decreases the odds even lower. No. Hsv symptoms will not come on within 12 hours. The first thing he would probably notice would be lesions. That being said the odds are les than one in a thousand.