You could be cheating on your partner without even realising as experts reveal little-known types of infidelity

Did you know that cheating on a partner without knowing so is a possibility? That's according to a relationship expert who has revealed exactly how people are unfaithful day-to-day.

The lines for cheating are always a bit blurry. While many couples follow a general unwritten rule book, some tend to waver slightly.

What one couple believes is unfaithful, might be completely okay in another relationship.

And in the age of social media comes a whole new way to be unfaithful to your partner.

There are endless temptations and possibilities, but knowing right from wrong is pretty basic.

However, did you know that cheating doesn't always involve another person?

There's actually a fair few ways that infidelity takes place without us even knowing so, apparently.

Speaking to Women's Health, relationship therapist, Max Lundquist, revealed five ways it can happen.

Cheating without knowing can happen, according to experts. (Getty Stock Images)

Physical cheating

This is the one that is pretty non-negotiable across the board.

It comes as no surprise that being physically intimate with another person is considered cheating on your partner in a committed relationship.

There are of course different levels to intimacy, and according to experts, it's up to you and your partner to work out what you are and aren't okay with.

Sexual fantasies about another person

Fantasising about people you find attractive is a pretty common thing to do, whether you're in a relationship or not.

However, frequently day-dreaming about someone you see quite often could lead to something more, according to Lundquist.

Having romantic feelings towards someone else

It's commonly known as 'emotional infidelity' but, as you can imagine, the lines are particularly blurry.

Lundquist said: "There is an undertone of disloyalty here."

While we're encouraged to have multiple loving relationships with people in our lives, this becomes a problem when secrecy comes into play.

According to the expert, only seeing someone when your partner isn't there is a good example.

Hiding spending habits could cause problems. (Getty Stock Images)

Secret spending

This could be one we're more commonly guilty of.

Lundquist says that hiding your spending habits from your partner could be considered unfaithful.

He says it's an issue when spending in a relationship impacts both of you.

The expert added: "This can cause problems and I would say it's unfair not to disclose these activities as you are bound to get found out anyway."

Secret social media activity

Social media has made it easier than ever to cheat on your partner.

But Lundquist has a very different take on our online activity.

He actually suggested that spending more time on our phone than with our significant other could be a form of infidelity.

'Obsessive' behaviour on social platforms could lead to being less engaged with a partner.