Alfie Moon is to ask Kat for a divorce when she returns to EastEnders, according to The Sun today.
Alfie makes the decision after realising how close he is becoming to Kat's sister, Little Mo.
A source told the newspaper, "Alfie's been getting closer and closer to Mo and decides his marriage to Kat is over.
"He decides to ask for a divorce, but then she returns to the Square determined to win him back. Kat puts up a fierce fight for him."
Producers originally planned to reunite the couple straight away, but the newspaper claims that they will now have a rocky time ahead for the rest of the year.
Jessie Wallace, who plays Kat, returns to the EastEnders set next week.