If you put this situation in any form in google and you will always get answers saying no risk and 0 risk. Yes that is true and you have no risk at all. Enjoy your sex life protected (intercourses with condom and no break in condom)
Mutual masturbation is not a risk for HIV. Any fluids he may have had on his fingers before he touched your anus had been exposed to air and temperature changes that would have rendered the virus, (if any) inactive. (Unable to infect) YOU HAD NO RISK AND DO NOT NEED TO TEST