Nice fantasy JJ.   HIV risk via unprotected sex.....

anal receptive  1.4%  (17x more than vaginal receptive and 35x more than vaginal insertive)

vaginal receptive  .08%

vaginal insertive  .04%

Clearly, intestinal intercourse is a very bad idea.

http://www.catie.ca/en/pif/summer-2012/putting-number-it-risk-exposure-hiv