Alan Halsall is convinced Jennie McAlpine is a "vampire" because he joked she "demands an umbrella" if the temperature hits more than 12 degrees.
The 'Coronation Street' actor - who plays Tyrone Dobbs on the ITV soap - quipped his on-screen significant other (Fiz Stape) cannot let the sun "actually hit her".
He said: "If the temperature gets above 12 degrees and the sun is out Jennie demands an umbrella.
"I'm convinced she's a vampire, the sun cannot actually hit her.
"Umbrella up, factor 50 on. I'm like, 'It's 12 degrees.' "
But Jennie has put it down to her family hailing from Scotland.
She added: "I've got Scottish roots.
"It's my Celtic skin.
"We can't go anywhere near it, we just can't."
But the pair do agree on "who can do no wrong" on the soap, with them both admitting that is Isabella Flanagan (Hope Stape).
Speaking in a joint interview with STV, Alan said: "She knows all of our lines, she knows all the stage direction, she knows everything.
"The director gives her a note and she nails it."
Jennie added: "She comes up with solutions. She came up with one for the props the other day.
"She said, 'Why don't you do that at the top of those stairs? That would make it easier.' 'Oh yeah, we've been looking at that for 20 years, we didn't think of that.' "
Alan said: "Directors pet, 100 per cent."
Jennie returned to the soap last year to reprise her role as Fiz after going on maternity leave.
And she revealed her and her husband Chris Farr - who have two children together, five-year-old son Albert and 15-month-old daughter Hilda - have a weekly meeting to "coordinate" their schedules and plan child care.
She said: "Being a parent is flipping hard work and the juggling is crazy. Me and Chris have a meeting every Sunday night to coordinate the coming week and we have a family timetable stuck on our fridge."
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