As we reported at the weekend, Kat will get passionate with a mystery guy at the Queen Vic on July 4, following suspicious interactions with a number of Walford men.
Max, Ray, Derek, Michael and Jack are the five suspects in the storyline - but even the EastEnders cast are in the dark over the outcome, as all scenes with Kat and her lover are being filmed with an extra to avoid leaks.
On the morning after her infidelity, Kat (Jessie Wallace) feels terrible over her decision to cheat on husband Alfie. However, it's a mistake that she finds it difficult to forget as her mystery man plagues her with constant phone calls and texts.
At one point, the guy even phones the Queen Vic's landline and when Alfie (Shane Richie) answers, he clearly recognises the voice on the other end. Completely oblivious to what's really going on, Alfie tells Kat that her "favourite fella" is on the line.
Kat is enraged by the behaviour of her lover and immediately decides that she can't let the affair continue.
However, Kat's resolve is tested when the man in question won't take no for an answer over the next day or so, continuing to call and text despite her rejection.
Still feeling unsatisfied in her relationship with Alfie, the landlady eventually meets her lover outside in the alley when he informs her that he's waiting for her.
Kat is initially intending to tell him to go away, but in the end, she can't resist his advances when he pulls her in for a kiss - and it's clear that this relationship will be going on for a while. But who is her persistent male admirer?
EastEnders airs these scenes on Thursday, July 5 and Friday, July 6 on BBC One.
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