Being cheated on sucks. We’d all quite like to avoid it happening, really. If it does happen, you’re then presented with a tough call: do you work through things and try to rebuild trust?

Or do you call off the relationship and move on? An important part of making that decision is understanding why the person cheated – and what their infidelity says about their view of the relationship.

One expert in affairs says there are two distinct types of cheating, and knowing the difference is crucial. Speaking to BusinessInsider, Tammy Nelson, a sex and relationship therapist who works for Ashley Madison, said that affairs can be separated into two categories: A way to end a relationship and a way to fill the gaps in relationships (the emotional gaps, you dirty-minded people).

She describes the first category as a ‘can-opener’ affair. That’s when you want to leave a relationship and don’t know how to do it, so you cheat, knowing it’ll break you apart.

A person having a can-opener affair might not be aware of the reasons they’re doing it, but on some level, they’re looking for a way to end their main relationship.

Sometimes cheating can seem easier than confronting the reality of what’s gone wrong.

Tammy says women are more likely than men to have can-opener affairs. Men, meanwhile, are more likely to have affairs of the second type, as ‘a way of filling that one part of their life that their marriage doesn’t’.

So that might be an affair with someone who shares a fetish your partner isn’t into, or having an emotional connection with a different person because your partner is too stressed to talk things through.

The person who has this type of affair doesn’t want to break up their relationship – they’re just trying to have it all.

This backs up previous research from Ashley Madison, which found that the most common reason people sign up to the affairs site is because their relationship has ‘lost its spark’, followed by boring or infrequent sex.

The site also found that 54% of users said their affairs enhanced their marriage, as they provided excitement and sex without the need to leave the marriage.

So those people fall firmly into the second category.