Imagine the therapist has a new program he (or she!) is testing out on couples. The idea is to teach them to communicate better with language and touch. He has them wearing helmets with viewscreens inside such that they can speak and it translates that to text. Other than the helmet, they are to wear nothing. While this hat stops any oral communication or oral sex, it's supposed to get them to pay attention to what words are actually said.
All those intentions are wonderful, but the therapist accidentally cross-matches two married couples, and both couples get all the way to sex before finding out, as they're so focused on attempting to get words right.