• Ashley Madison is a website for married people seeking affairs. Sex therapist Tammy Nelson is its resident relationship expert.
  • Nelson said many people wind up cheating on their partners because they lack passion in their marriage.
  • That's why Nelson recommends having an "affair" with your spouse, meaning you put in the effort to add something forbidden or exciting into your romantic life.
  • However: You have to plan it.

Here's the fantasy. 

You come home to your partner, "sweep the dishes off the kitchen table, and say, 'Oh my god, take me now.'"

But Tammy Nelson isn't buying it. "Twenty years later, and with three kids and a dog, that's not going to happen."

Nelson is a sex and relationship therapist; after about 30 years in practice, she recently joined Ashley Madison, a website for married people seeing affairs, as an outside consultant.

See also: The relationship expert at one of the most popular affair websites says there are 2 distinct types of cheating among modern couples

The fact that the scenario described above is so unlikely to occur in a long-term relationship is what drives some people to stray,  Nelson said.

"That's the fantasy of an affair, that you'll have that impulsive excitement."

Nelson isn't explicitly "for" or "against" cheating. In fact, she suspects that people will always have affairs.

But she did propose a workaround for anyone who feels like they can't tolerate the lack of passion in their marriage, and need to look elsewhere for it.

Of that "impulsive excitement" she mentioned, Nelson said, "You can have that in your marriage — if you plan it."

See also: Having a good sense of smell could be better for your sex life — here's why

This is, admittedly, not a very sexy idea. But according to Nelson, it works.

"What bores people in their sex life is that it's all acceptable. Like, this is great sex, but it's all vanilla sex. It's all fine and good and acceptable and we're not doing anything naughty."

The solution? "You have to have an affair with your spouse. You have to make something about your marital sex feel dangerous."

Passion doesn't just materialise out of thin air

Other relationship experts agree on the benefits of "feigning an affair" with your spouse.

As sex therapist Moushumi Ghose told HuffPost, "Role-playing is a great way for couples to reignite that which may have been lost, by stepping out of their role as dutiful wife, husband and caregiver and getting back to that place where they can throw caution to the wind and embrace that raw, lewd side of themselves."

Even if you don't go so far as to meet like strangers in a bar, the key thing to remember is that you'll need to put in some effort.

Relationship expert and marriage counselor Rachel Sussman previously told Business Insider, "People think, 'Oh, [passion] should just be there,'" Sussman said. "No! It shouldn't just be there. You have to create it."

Bat Sheva Marcus, the sexual dysfunction specialist and clinical director of The Medical Centre for Female Sexuality, even recommends scheduling sex on the calendar.

All this means you'll need to have some frank discussions with your partner about intimacy. "If you can have those conversations," Nelson said, "then it can be just as hot as affair sex — without the risk."

Receive a single email every morning with all our latest news: Sign up here.

Also from Business Insider South Africa: