For as long as couples have roamed the earth in committed relationships, there has been infidelity.
While the taboo topic of behind-closed-doors affairs isn't often discussed over the dinner table, recent Married At First Sight cheating scandals have thrown the matter back into our consciousness.
Alarming data collected by leading dating site Ashley Madison shows that 53 per cent of cheaters admitted they strayed from their relationship due to lack of intimacy with their partner, while 33 per cent said they were seeking "more fun" in their lives.
But do people in "happy" marriages ever cheat? And can a relationship plagued by deceit ever overcome infidelity?
These are the questions we put to sex and relationship expert Dr Tammy Nelson, who helped us break down age-old cheating myths and shared sage advice for anyone whose partner has been unfaithful.
Tammy, who quite literally wrote the book on cheating; Open Monogamy; Co-Creating Your Ideal Relationship Agreement, says that people don't necessarily have to be "unhappy" in their marriages to look elsewhere for a romantic connection.
"If [a person feels] like they're not heard or if they can't find a way to be who they want to be in their current relationship, they will look outside their marriage – not necessarily to be with another person but to become another person," she tells Now To Love.
"In fact, studies show that up to 56 per cent of men and 34 per cent of women who have affairs described themselves at the time as being in happy marriages. They also said that they loved their primary partners and were having good sex."
However, if cheating has been discovered, it doesn't always have to spell the end of a relationship or marriage.
"The discovery of an affair can be a wake-up call; an opportunity to create a stronger, more vibrant relationship with a current partner, if both are committed to working through issues and creating a new monogamy agreement," Tammy says.
"It can feel like a scandal when one of you cheats, it betrays the personal boundaries you have for yourself and blows apart the vision you may have had for your future.
"Despite the incredible pain of the infidelity it is possible to create a new monogamy: a new relationship in which the needs and desires of both of you are explicitly stated and this can be a reboot for both of you."
Tammy says that for anyone toying with the idea of cheating on their partner, they should ask themselves the following questions before taking any action to do so:
"Can you live with yourself? How does integrity play a part in your relationship? How will your partner feel if they find out? Would it be easier to talk with your partner first, asking for your needs to be met or negotiating an open monogamy agreement?"
Tammy also says there's a grey area when it comes to "emotional cheating," which, by definition is the bond between two people that mimics the closeness and emotional intimacy of a romantic relationship, while not being physically consummated.
"Whether its emotional, romantic or sexual cheating, you know if it's cheating if it's violating your commitment," she says.
"If you don't want your partner to know about it, and if you feel you need to hide it from them."
But once someone gets trapped in a cycle of cheating on their partner, they often struggle to find a way out of their web of deceit.
"If you find that you are chronically cheating on your partner, it may be a sign that you aren't suited for marriage, or that you want out. Be brave and confront the problem. Get professional help," Tammy says.
"Counselling can help you define what you are looking for and give you the skills you need to communicate with your partner and either let them out of a bad marriage or give you the tools you need to stay in a potentially good one."
We've all heard the age-old saying "once a cheater, always a cheater", but is this true or simply a myth created to lump unfaithful people into a title they'll never escape from?
"Many people assume that infidelity is a symptom of a fundamental problem in a marriage or committed relationship, ignoring the important questions of whether monogamy is even possible for the average person who lives to be almost 90," Tammy says.
"Perhaps affairs are a natural result of long-term relationships, maybe they are a way to stay married when we are expected to live with one partner for more than half a century.
Tammy says that this doesn't necessarily mean that we, as humans, are not committed to monogamy, but that sexual fidelity is not synonymous with romantic monogamy.
"Companionship and our ideas of monogamy might be more fluid than they have in the past when we lived to be an average age of 38," she explains.
Incredibly, Ashley Madison's survey found that 70 per cent of cheaters say they do not feel guilty for doing so.
"Our members have told us that they have experienced many benefits from their decision to stray including regaining their confidence, feeling empowered, and feeling desired again," says Isabella Mise, director of communications for Ashley Madison.
"Infidelity isn't something that people fall into, there is often times a shift in their relationship, whether their spouse feels it or not, that leads them to choose happiness. Our members are taking control of their lives by adding what's missing.
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