FYI, I'm not a doctor. I don't even play one on television.
Anal sex is always more risky than oral. More opportunity for microscopic skin tearing, etc.
In the grand scheme of things, we now understand that if you're HIV+ with a zero-viral load (on meds) that you're almost definitely not going to transmit the virus to someone else. That's awesome, but it also requires a leap of faith in believing that someone is on those meds and keeping up with their health as they say they are. This is why PrEP is a tool that any HIV-, sexually active guy needs to take.
As always, the responsibility for your own health falls on your shoulders.