Mackenzie (Emily Weir) and Levi’s (Tristan Gorey) affair has been going on for a number of months now, and other than Mac’s housemates Tane (Ethan Browne) and Mali (Kyle Shilling), nobody has any idea.

Mackenzie was Levi’s patient when she suffered a spontaneous coronary artery dissection (SCAD) late last year, but the pair soon grew close and found themselves kissing.

When Levi revealed that he had a wife, Mackenzie briefly put a stop to things, but they struggled to stay away from each other, and it wasn’t long before they embarked on a full-blown affair.

The pair have almost been caught out on a number of occasions, most notably when Alf (Ray Meagher) walked past them as they were kissing near the Surf Club.

Thankfully he saw nothing, but it was a very close call.

On another occasion, Felicity turned up unannounced at the farmhouse and was concerned to find Mackenize’s doctor paying her a house call.

Flick assumed that Mac’s doctor paying her a personal visit meant another health scare, but thankfully, they were able to convince Flick that it was nothing to worry about.

Eden has nearly landed her brother in it on a number of occasions.

Each time Levi has made one of his secret visits to the bay, he’s told wife Imogen (Georgia Blizzard) that he was visiting Eden. The siblings recently reconnected after decades apart, and reconnecting with his sister offers Levi the perfect excuse for his illicit trips to Summer Bay.

Yet Eden has been oblivious to this, and at one point called Imogen to ask where Levi was, only to discover that Imogen thought that they were both together.

Thankfully, Eden managed to think on her feet and avoid landing her brother in it. Confronting him, Levi revealed that he just needed a break from Imogen, with talk of children beginning to stress him out.

In recent weeks, Mackenzie’s jealousy over Levi’s continued relationship with his wife saw her make a dangerous move.

When Eden (Stephanie Panozzo) invited Imogen to visit Summer Bay and the pair headed to Salt, Mackenzie took the opportunity to get to know Levi’s wife, sitting down with them for a cosy coffee and a chat.

Levi was furious when he realised that his wife and his bit on the side had met, and it nearly spelt the end for him and Mackenzie, but Mac eventually apologised for letting her jealousy get the better of her.

Now, in upcoming scenes, the truth comes out once and for all.

A new promo, which aired after Wednesday’s episode, shows Levi and Mackenzie kissing right in the open (will they ever learn?), as Eden walks around the corner and catches them.

“Are you kidding me? You cheating liar!” she exclaims.

Eden and Levi were estranged for years, after their dad had an affair of his own. A teenage Eden cut her father out of her life, but Levi went to live with him, causing Eden to cut her brother out of her life too.

Eden lays into her brother outside the Surf Club.

“You are sleeping with one of your patients, what is wrong with you?”

Levi assures her that he isn’t throwing his relationship with Imogen away for nothing.

“My feelings for Mackenzie are real,” he insists.

Yet Eden adores Imogen and can’t believe her brother would risk throwing it all away.

“You have a wife who loves you!”

“You cannot tell her,” Levi pleads, but it falls on deaf ears.

“You do not get to tell me what to do.”

When Mackenzie and Levi reconvene, Mac is panicked that the whole world is about to find out about their affair.

“Eden could be on the phone to your wife right now.”

The promo tells us that the exposed affair will drive a wedge through the bay, and it’s not just Levi’s relationships with his sister and wife at risk.

As Mali gets given the cold shoulder by Eden, he asks her, “Have we got a problem?”

Eden then rips into Mali for the fact he knew about Levi and Mackenzie’s affair and didn’t say anything.

“You’re giving my cheating brother a place to stay. You lied to my face.”

The promo tells us that friends will become enemies.

“A married man?” Flick asks Mackenzie as the two have a tense conversation in Salt. “I can’t believe you’d go there.”

“Just leave it, Felicity, okay, this has nothing to do with you,” Mackenzie replies.

“I don’t know how you can live with yourself,” Flick tells her business partner.

With half of Summer Bay now knowing the truth about Mackenzie and Levi, it can only be a matter of time before Imogen finds out.

Will it all be worth it?