Make him wear a condom!
I recently started dating someone and told him my status before we had sex. Of course, as my virus works, I talked about it and I got an OB. So we had one week where we had no sex. He was really nice about it considering it was right at the start of our relationship. He's been informed of the risks and chooses not to wear a condom some of the time. I'm also aware of my fertility, so I make him put his raincoat on most of the time.
And check out some of Chis' other works here and on his site for non-valtrex ways to keep the little beasties in the house and not romping on the yard :)