A Republican member of the South Dakota House said in a Facebook post that he's opposed to marriage equality because anal sex “isn't good.”

Rep. Steve Hickey's post, titled A One Way Alley for the Garbage Truck, is a response to a planned federal lawsuit to South Dakota's ban on gay marriage.

(Related: South Dakota AG Marty Jackley says he will defend gay marriage ban.)

“Pardon a crude comparison but regarding men with men, we are talking about a one-way alley meant only for the garbage truck to go down,” Hickey wrote.

Hickey also called on the medical establishment to speak out against gay sex.

“Certainly there are board-certified doctors in our state who will attest to what seems self-evident to so many: gay sex is not good for the body or mind. … South Dakota docs, it's time for you to come out of the closet and give your professional opinion on this matter like you capably and responsibly do on all the others. Somehow the message we are presently getting from the medical community is that eating at McDonalds will kill us but the gay lifestyle has no side effects. Truth be told it seems self-evident the list of side effects would read far longer than anything we hear on a Cialis commercial.”

Speaking to doctors, he added: “It is not unloving to tell people you don't have to have sex with and marry someone to love and be loved by them.”

In a phone interview with Talking Points Memo, Hickey acknowledged that anal sex is also enjoyed by heterosexual couples. “Absolutely,” he said, then changed the topic to the “health of homosexuality.”

Hickey, who earlier this year introduced a bill that seeks to allow individuals and businesses to discriminate against gay couples, told TPM that marriage equality is not “in my top five of legislative priorities.”

Hickey lamented that doctors are being discouraged from telling the truth about gay – but not straight – anal intercourse: “I do believe, and I've heard enough medical people talking about the intimidation factor and silencing that's going on. And you just don't talk about it. You know, you practice medicine and it's an issue of politicized medicine and junk science and agenda-driven studies. When the average person can just, you know, what's self-evident is that [anal sex] isn't good.”

Hickey also submitted his letter to be published in the Argus Leader.