Since this is a new partner it's best to use condoms, even during masturbation. You can go to the Dr or clinic to both be tested. If neither of you have any STD's then you're fine. If one of you has herpes it can be given to the other one even if you use condoms because of skin to skin contact. So, you would have to be very careful about what you do and when you do it because if there's a breakout the chances of getting it are higher. Usually if you get infected the bumps and sores will show up pretty fast, but not always.
Herpes can remain dormant for a long time. A person can be a carrier who does not have any symptoms but can infect others. It was your first act. Was it same for him?.You will hear from other members, advising you one this issue.