LOS ANGELES

A FEW years ago, Michelle Borth went topless for a movie, and she thought: “That’s it. That’s my last topless scene.”

Then she read the script for the new HBO show “Tell Me You Love Me.” The show required frontal nudity and such explicit sex scenes that the first question asked at a press conference with television critics last July was:

“Did anybody actually do it?”

The answer was no, but Ms. Borth, who plays Jamie in “Tell Me,” is not faulting anyone for wondering.

“It’s not supposed to be like any show,” Ms. Borth, 29, said. “To keep it tame doesn’t do justice to what we’re doing, which is an unfiltered, candid look at relationships, and that includes sex.”

Certainly, real sex in acting is rare, but recent offerings in television and film are pushing the boundaries. Some critics have called “Tell Me” nothing more than soft porn, and even people in the entertainment industry question just how much explicitness is necessary. Just how graphic, they ask, must sex scenes be to make a dramatic point?