EastEnders’ Jean Slater’s whole world comes crashing down next week, when Cindy Beale broadcasts a video of Harvey Monroe and Kathy Cotton kissing in The Vic.

Choosing her moment for maximum impact, shunned Cindy exposes the affair to get back at her mother-in-law, but Jean is crushed in the process. Will Harvey come clean about the extent of his feelings for Kathy, or lie to protect Jean?

The week begins with Harvey’s affair still safely under wraps, as he helps the Slaters prepare for a family camping trip. However, his efforts to play peacekeeper backfire when another war breaks out between Lily and Stacey. Exploding with frustration, Harvey storms out and heads straight to the café to see Kathy.

Two-timing Harvey’s moaning doesn’t go down well with his secret lover and Kathy gives him the brush off. At No.31 the Slaters make up, throwing together a makeshift camp when their trip falls through – and Harvey returns home to this happy family scene, overwhelmed with guilt. But a bigger surprise awaits…

“Harvey’s heart is full of Kathy – but then Jean proposes,” reveals our source. “Harvey feels sick at the sight of Jean down on one knee, beaming with joy. But when he doesn’t respond, Jean runs away, seeking advice from Kathy of all people.”

While Jean confides in the other woman, Harvey prepares to come clean. But when Jean gets home, Harvey’s words come out all wrong and she assumes he’s agreeing to marry her after all.

Mortified Harvey makes a quick escape as the Slaters celebrate, but when he shares an illicit kiss with Kathy, he has no idea Cindy has seen it all – and has recorded the whole thing.

The Square is soon abuzz with news of Harvey and Jean’s engagement and the Slaters head to The Vic. The pub is also playing host to a party for Lauren Branning and Peter Beale’s new baby, but Cindy’s arrival causes a stir as the Beales make it clear she’s not invited.

“Cindy has nothing to lose at this point,” says our insider. “If she’s hurting, she wants everyone else in pain too. She takes great delight in pressing play on that video and ruining lives.”

The Slaters and the Beales reel at Cindy’s footage, as newly engaged Jean demands answers from the man she loves.

Later, at home, Kathy tells Ian Beale about her affair and the feelings she has for Harvey – but will he be as honest with Jean and finally leave her?