since he's unsure if he even had sex let alone if it was protected or not, he should follow up on full std testing to properly cover his bases. he can get tested for gonorrhea, chlamydia, ngu and trich after 1 week post encounter. syphilis after 6 weeks. herpes, hiv and hepatitis after 3 months. until he can properly cover his std testing bases, he and his regular gf should only have protected sexual contact.
grace
He'll have to wait 3 months to test for hsv 1&2 to get a conclusive result.