I've barebacked sincemail I was 16, I never liked my men wearing condoms! I always knew it was a matter of when I would get hiv not if. However I practiced caution & didn't get it until i was 49. My point being if he is barebacking he is probably aware of the risk. And if he's as open as you say he probably doesn't care. When I got hiv I bottomed for a younger man we were already nude when he told me ,and had done it a couple of times before he found out. I wanted his cock and cum so bad at the time i threw caution to the wind. I enjoyed having sex with him. Bareback bottoms love having men in us and we love having cum in us!
If the two of you know the facts & can live with it fuck him raw you will both love it.