There’s a lot of sex in Showtime’s new series Masters Of Sex, an explicit depiction of the relationship between William Masters and Virginia Johnson and the groundbreaking research they did on the subject — a lot of it through direct observation of thousands of sexual encounters between hundreds of male and female subjects.

Loads and loads of sex. Sex as an intimate act of love and/or passion, sex under hot lights while wired like lab rats and being closely watched by scientists. Sex with strangers, sex with lighted dildoes.

Sex sex, sex, sex, sex.

So much sex, complained one critic during the Masters Of Sex Q&A session at TCA Summer TV Press Tour 2013, it was “challenging to tweet some of this.”

“I never thought I’d get used to having a naked woman in front of me masturbating with a glass dildo…but I actually broke that barrier on the show,” series star Michael Sheen told TV critics this afternoon. One critic wondered how the series could pull off this much sex without getting into “tee-hee” territory. Sheen shot back, British-ly, “We’ve just had a slightly inappropriate look into your sex life. We all thank you for that.” The sex scenes, Sheen said, “had to be absolutely believable.” Did they get it right? “I don’t necessarily think any show gets it absolutely bang on from the beginning,” he said, adding, “Everything has to come out of the situation” and be “bedded in real situations.”

On the other hand, co-star Lizzy Caplan acknowledged “If you put a lighted dildo in front of Beau Bridges’ face” you’re going to get a laugh. Bridges plays Barton Scully, chancellor of Washington University where Masters was a faculty member and gynecologist and began his human sexuality research in the mid 1950s. Johnson answered a help-wanted ad and became his assistant.

Another critic wondered if any of the actors were embarrassed doing the sex scenes or were they “always excited, and did any of you ever go to Catholic school and did it affect your performance?”

Seriously — we can’t make this stuff up.

The series is based on Thomas Maier’s book Masters Of Sex: The Life & Times Of William Masters And Virginia Johnson, The Couple Who Taught America How To Love, which came out in ’09, and for which Maier interviewed Johnson extensively. Masters died in 2001. Johnson died just last week, without seeing any footage of the new series, which is scheduled to debut September 29. Showtime programming chief David Nevins had said earlier in the day that Johnson “kept in touch with” the series through Maier, but “her physical state and mental state were not so good in the last year, so she did not see any footage before she died.”

Caplan acknowledged she knew nothing about Johnson before taking the role. She credits Johnson and Masters with helping women to accept their sexual curiousity as healthy and “not dirty…Before Masters and Johnson, no one was telling women that. It was always their fault — and that’s some bullshit.” Additionally, Caplan told TV critics, she learned that “people’s masturbatory techniques are lot like snowflakes.”

“Cold, and you end up wet,“ Sheen cracked.