My question is: what are the actual chances of him catching the virus genitally (from me)? From what I’ve heard, I believe the chances are very low – if not zero – since he’s already HSV-1 positive. Is there new scientific evidence about HSV-1 genital-to-genital transmission, or cases of multiple locations? I feel like HSV-1 is less studied.
HSV 1 is less studied, true. Because he already has HSV 1 orally and your HSV 1 genital infection sheds rarely, he is extremely unlikely to acquire HSV 1 genitally.
I think you can let this partner know that you also have the cold sore virus. At some point, you may also wish to share that yours is genital and that transmission to him is highly unlikely, given that he already has this virus. If the relationship is meaningful, in my opinion, you should work up your courage and talk about this.