How to determine whether a relationship is true?

Figuring out whether the man or woman you’re with is the ever-elusive ’one’ is no mean feat.

But, if a new checklist is to be believed, it’s rather simple to work out.

According to a study, couples who talk about bodily functions, have access to each other’s passwords and shower together are the most committed.

Planning a holiday, driving each others’ cars and having a key to your partner’s flat are other signs that a relationship has got serious.

Researchers quizzed couples on the different stages of their relationship to determine the top signs that indicate a couple are past the "seeing each other" phase and taking things into more serious territory.

Posting a "loved-up" photo on Facebook, changing your status to ’in a relationship’ and being introduced to wider friendships circles also show couples are the ’real deal.’

Meeting potential in-laws, staying overnight and divulging salary details also prove that couples are the ’real deal.’

The study also highlighted that couples deem a relationship more serious when they get more comfortable with each other - which means seeing each other without make up, showering together, lounging around the house in pyjamas and even discussing intimate health issues and bodily functions.

Other relationship milestones include meeting the parents, becoming the ’plus one’ on all invites, seeing each other through an illness and comfortably phoning each other at work.

Buying a dog or cat together, choosing their partner’s favourite foods in the weekly food shop and sharing their friends secrets are also sure signs that you’re with the one.