First of all, do you have type-1 or type-2 genital herpes? If it's type-2, then there is very little risk to your partner as far as oral sex goes. Type-2 prefers the genital area and, although it's not impossible, it is highly unlikely that you will spread it to his mouth. As always, avoid all sexual contact when you have or think you might be getting an outbreak.

Now if it's type-1, that strain is happy to live in both the genital and oral areas. But because it prefers the oral area, type-1 genital herpes does not shed as much because it's away from its "home." Therefore risk of transmission is somewhat lowered. Once again, avoid all sexual contact when you have or think you might be getting an outbreak. Everything that I've been able to dig up--and there's not much anyone has to say about type-1 genital-to-mouth transmission, which tells me it's not a massive problem--has said that, while it's not impossible, there is not a huge risk of transmission. I have also heard that when you take Valtrex as daily suppressive therapy, that can reduce viral shedding up to 95%.

Bottom line: It sounds like you are doing everything right as far as taking suppressive therapy and communicating with your partner. While the risk of transmission is low as long as you stay on the meds and listen to your body, both of you have to understand that there is always the possibility of transmission. Of course there's the possibility of transmission having vaginal sex even when you use a condom. It's not perfect. Make sure you both understand the risks involved before making a decision and keep communicating.