Congratulations on the success of your therapy. It is great to hear.
Regarding your potential infectivity for your HIV negative partner, there are no sure answers. Let me tell you what we know:
1. The likelihood of transmitting infection to your partner would vary with your viral load. In studies done in Africa (there have never been studies of this sort done in the US), the data show that the higher the viral load, the more likely transmission is to occur. With undetectable viral loads in Africa, sexual transmission was very, very rare. (another caveat to these data is that the data are all for heterosexual intercourse. There are currently studies underway to evaluate how risk for transmission changes with therapy
2. Even in persons with non-detectable viral loads in blood, studies show that virus may be present in genital secretions (they do not differentiate between pre-ejaculatory fluid and ejaculate)
3. You are asking about ano-genital sex and the data are for heterosexual genital sex. This is important since the risk of transmission is higher for anal sex (transmission estimate is 1 in 100 exposures) than it is for heterosexual genital-genital sex (estimated risk is 1 in 1000 exposures)).
4. If either of you have any inflammation present, the risk of transmission goes up. The reason I bring this up is your mention of some blood from your partner.
Each of these points I made comes from different studies. No one has put all of the pieces together. Thus, to summarize, I would say that for you to have unprotected sex with your partner, despite your wonderful response to therapy, there still is some risk to him of getting infected. The risk of transmission will be about 100 times higher for rectal sexual contact than for oral sex. My recommendation is that barrier protection should be used, particularly for rectal sex. I suspect that is not what you were hoping to hear but it si best advice I can give you. Hope it helps. EWH