You may have heard of the honeymoon period in a relationship, but did you know there are four other stages - and it can take years to work through them.

There are five stages of grief and five in a relationship, according to a popular relationship expert.

Kevin Pasco, 31, from Vancouver, Canada, recently shared the details of these phases, warning: 'Most people don't even make it to stage three… let alone stage five.'

In a now-viral TikTok video, he outlines each era, starting with the honeymoon phase, which he says may last for sixth months to a year.

Kevin Pasco, 31, from Vancouver, Canada, recently shared the details of his 'five-stage' romance theory

The relationship coach warned: 'Most people don't even make it to stage three… let alone stage five' 

Kevin described the honeymoon phase as 'rushing feelings of love, rose-colored glasses, bonding via similarities' between the new couple.

But the next was the power struggle phase, which is when you start to pick up on the differences between yourself and your partner.

'You start noticing that all those similarities don't seem so great anymore, because I see all the differences'  Kevin said.

The relationship coach said this stage usually ends in two different ways.

'One, they stay in the power struggle phase - i.e. the old couple who still bickers and fights,' he listed.

'Or people end up breaking up,' he said. 'They say "nope, this is too much. I can't love you for your differences, I can't do this with you anymore."'

Kevin said in this situation, they end up going back to the honeymoon phase - except with someone else.

'They repeat this very toxic cycle of honeymoon, power struggle, breakup,' he explained.

@kevinxpasco

The 5 Stages of relationship & how most people don’t even make it to stage 3… let alone stage 5 #relationshipstages #emotionalintelligence #relationships #dating #relationshiptipsformen #healthymasculine

♬ original sound - Kevin Pasco | MEN’S COACH

The video was flooded with praise for Kevin's theory as one wrote: 'I love your advice. Brings couple together rather against each other'

The content creator said the way to get out of this is to move on to phase three, which is adaptation and acceptance.

'Loving them for your differences, accepting them fully, and seeing the beauty in them,' Kevin explained.

He added the key is to  be able to adapt.

'You are creating a new energy of using the likes and the differences and between you two to create something brand new,' he further explained.

According to Kevin, most people don't even make it to phase three.

'It is every difficult to do, yet all human beings are on this path - eventually you're going to get it,' he said.

The fourth phase is commitment, which happens after you've accepted the person for who they are and you commit together to building a life.

Finally, the fifth phase is oneness - when you are totally in tune with your partner.

'It takes decades for you to get to stage five,' he shared, citing psychologists and therapists amongst professionals he has talked to.

Kevin stressed you had to go through all the stages 'in order' to reach the final one, which is the goal.

The relationship expert said it can take decades - if ever - to get to stage five of the theory. He is pictures here with his girlfriend

'You have to have years and years of experience and knowing the person to get to that point,' he continued. 'So chances are, if you're questioning if you're on stage five and you've only been together a little minute - you're probably not there yet.'

Kevin also revealed the key to moving from stage two to three, which is anchored in accepting your partner fully.

'You must fully accept the person for who they are, and be okay with them not ever changing in the future,' he shared. 'You need to have years and years.'

The video was flooded with praise for Kevin's theory as one wrote: 'I love your advice. Brings couple together rather against each other.'

Another added: 'This is really insightful. Nothing but facts. You're right about not getting past phase three.'

And a third simply said: 'This makes so much sense.'