Thanks for this post! As a woman, I have been advised strongly against anything, even a finger going into my rectum so I am steering clear for the integrity of my pouch--I don't want to mess around with that delicate, altered anatomy. But, I do also get self-conscious about having sex sometimes because of the pressure sensations with sex and worry about leakage. I know as a gay man your experience is different but wanted to reassure you that I am sure most people have some insecurities at times with sex and sex play---as does everyone. With that said, I think that if you found you are comfortable with your partner enough to enjoy oral sex in that area---that is wonderful! I would be very cautious about taking it further because of the risk of possible injury 
Happy to hear you are healthy and enjoying life (and sex!)