Stella actress Michelle Collins has let slip that Karl (John Michie) will turn "very sinister" as he attempts to find a way back into his ex-partner's affections.
Karl Munro was kicked out of the Rovers' Return after his affair with Sunita Alahan, who he later moved in with due to having nowhere to go.
"I've got loads of other good stuff coming up where my ex [Karl] gets very sinister and becomes totally obsessed with me," actress Collins told the Daily Record.
The 51-year-old soap star, who famously played Cindy Beale on EastEnders for 10 years between 1988 and 1998, remains upbeat about her decision to join Corrie.
"I never envisaged I'd be in Corrie. If someone had told me years ago, I'd have said, 'You're joking', but right now it's amazing and obviously the toy boy storyline is great fun," she added.
Magazine reports have claimed that Karl will follow Stella's new hunk boyfriend Jason Grimshaw.
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