Do you remember the name of the episode? I'd like to see it.
Really reminds me of this from Slate -
The Monotony of Monogamy
I married my first sexual partner, and now I’m itching to cheat.
Question:
My wife and I have been together since high school, 17 years ago, and married for nine years. We are each other's only sexual partner. We both went through our own "seven-year itch," but nothing came of it, we were never unfaithful, and we stayed committed to each other. Now I find myself often wondering what it’s like to be with another woman. I have constant sexual fantasies about other women—it feels like my sexual hormones are at full throttle. I sometimes convince myself that it would be OK to have an affair. Then I realize my wife and I have something very special, and I put my sexual thoughts aside until they come up again. I haven't taken any action, but I just don't know what to do.
Answer:
Your letter makes me wonder if Romeo and Juliet had been able to run off and get married whether he (or she) would be writing a similar letter 17 years later. You two do have something very special. And if everyone were like both of you, there would be no need for the HPV vaccine. But it’s also understandable that given the prospect of having sex with only one person for the entirety of your life, no matter how delectable your partner or how deep your love, you might feel an intense desire to have a sexually profligate time at least for a little while. There are few who conduct themselves with more rectitude than the Amish. But even they understand that a lifetime of virtue can be hard to bear, and some allow their children a period of wildness called rumspringa. During it teenagers leave the community and wear fashionable clothes, drink, smoke, take drugs, and have premarital sex. Once this is out of their system, the majority choose to return to the community and accept its restrictions. You and your wife have such a good relationship that a few years ago, you were able to deal honestly with each other about the frustrations of committing so young.
Since you don’t mention children (which would vastly complicate how you act on your desires), I’ll put that aside as a consideration. I’m against your unilaterally deciding to cheat, but given your internal struggle now, it’s time for another painful discussion about your union. Perhaps the prospect of proposing a temporary separation, or experimenting with an open marriage, will make you realize you don’t want to risk capsizing your relationship. But if you continue to feel trapped and miserable, and she agrees to change the rules of your marriage, if only for a while, you two need to think hard about setting some boundaries for carrying this off, i.e., living apart and not dating people your spouse knows. Before you embark, be certain you understand that your marriage will not only be changed—it could cease to exist.