In theory, yes, but it's not longer a play or a musical if the sex is actually real, not simulated. It becomes a live sex show under the label of "artistic." Personally when it comes to plays and the like, I am a fan of implied sexuality instead of getting graphic. Have the actors wildly kissing, starting to fumble at each other's clothes, or suddenly throwing one another down onto a bed or couch, then cut to black. It's much more tasteful.

Would you ever go outside in your backyard nude and putz around in broad daylight?