With each lust, there is a natural inclination to an excess and variety. The glutton not only wants more food, but they also want more variety. The drunkard desires more alcohol. But nothing quite matches the ferocity of sodomy. Now sodomy is all forms of non-procreative sex, so that will include oral and anal sex between men and women. It also includes bestiality and sex with minors, elders, and sterile people.
The reason that sodomy is so addictive lies in the conjunction of the extreme pleasure of orgasm, the endless imagination of the intellectual mind, and the relatively low risk. I know that stds are a risk, but assuming that you have a handful of members who are regularly tested, one could engage in sodomy for years. Anal is the only major threat in the set of sodomite acts, and even that could be vastly mitigated with proper prepping.
At least with normative sex (i.e. straight sex), there runs the possibility of new life being created, thus making the sex act not merely about the participates. A new life has to be taken into consideration. Sodomy has none of that. The participates can use their bodies however they please, which inflates the ego and enlarges man's pride.
While the physical risks can be mitigated (i.e. regular std testing, careful selection), the mental effects are unavoidable and alarming. Sodomy is purely a hedonistic act, and the mind will further descend into more bizarre forms of sodomy to sustain an equilibrium of pleasure; masturbation to bikini models will eventually turn into full blown homosexuality, attraction to transsexuals, young boys, the elderly, animals, and so on. Not all sodomites will acquire all of the aforementioned perversions, but it is very likely if they continue down that path.
Sodomy is a very difficult urge to control, as I know from personal experience. I started out completely straight. Now I'm attracted to muscular men (as well as masculine, muscular women), women, trannies, midgets, elderly women, and so on. I have fantasies about raping and killing people who I dislike. These effects are alarming, and I am afraid that I will go further down the path of perversion; I've shuttered to think of what will become of me if I ever became attracted to children and animals. I'm trying to fight these urges as best as I can, but I enjoy the rush of sodomy more than religious duties.
I'm not sure what should be done about this issue, but perhaps sodomy can be treated like any other addiction.