How were you diagnosed? It's not common to only get sores inside the mouth. It's more common to get them on the gums with your initial outbreak, but not after.
I ask because I'm not sure this cut/sore on your gum is an hsv1 outbreak. In any case, even if it were, he already has hsv1. It would be very, very unlikely for him to get it on his genitals. It might happen if you had an actual outbreak on your lips that came into contact with his genitals and there was some friction, but still, that would be unlikely.
It's not something I'd be concerned about, especially since you're on acyclovir. :)