I was wondering if you could tell me what exactly is a "rim job?" Thanks!
A lot of people of all sexual orientations and genders enjoy analingus, but it is a form of oral sex that is very risky in terms of disease transmission. A lot of infections are contracted fecal-orally, like Hepatitis A, shigellosis (particularly caused by Shigella flexneri), pathogenic E. coli, salmonellosis ... the list goes on and on. Microscopic traces of feces on the anus can get into the mouth of the partner giving analingus. If those feces harbor anything particularly pathogenic, that can mean sickness (with diarrhea, bloody diarrhea, vomiting and fevers as major symptoms).
But like I said, a lot of people enjoy analingus. After all, the anus and perineum both have a lot of highly-sensitive nerve endings, and touch stimulation can be sexually pleasurable. Analingus can be done safely if the anus is covered with a dental dam or sheet of plastic cling film. A dental dam is a sheer square sheet of latex. It can be stretched over the anus to keep fecal germs away from the partner performing the analingus. The tongue should only come in contact with the dam or cling film.