Ryan Murphy’s next TV series will be about human sexuality, and it’ll run on HBO.

The guy behind FX’s plastic surgery soap “Nip/Tuck,” Fox’s high school musical dramedy “Glee,” FX’s anthology “American Horror Story,” and NBC’s gay-couple comedy “The New Normal,” got a pilot order for “Open.”

It’s described as a “modern, provocative exploration of human sexuality and relationships,” by Web site Deadline, which got the exclusive on the news.

Exploring human sexuality and relationships modernly and provocatively will be a married couple in their 30’s, a co-worker of the husband’s who is of indeterminate age, and a 40-something female who is — you know it’s coming — a yoga instructor. A.k.a. “limber.”

“This is really an adult show that is very frank in its depiction of sex,” Murphy told Deadline.

Gary Newman, chairman at 20th TV, where the show is being produced, hastened to explain the depiction of sex never feels gratuitous.

“Why not?” we’d have liked to have asked.

“It’s pay cable!” we’d have complained.

On the bright side, Newman insisted the sex on the show “feels organic to the subject matter.”

The subject matter being “sex.”