Emmerdale will shock viewers over Christmas with an incest storyline.
According to The Sun, Ryan Lamb will fall in love with Home Farms' Maisie Wylde, his half-sister.
Bigamist Mark Wylde (Maxwell Caulfield) had a secret first marriage to Ryan's mother Faye but neither Ryan nor Maisie are aware they're related.
Noticing the attraction between their children, Faye and Mark plotted to keep them apart, breathing a sigh of relief when mechanic Ryan (James Sutton) fell for Katie Sugden.
However over the Christmas period Maisie (Alice Coulthard) and Ryan get closer and finally share a passionate embrace.
Speaking to TV Biz, a source said: "There are lots of exciting storylines planned for Christmas, but this is a belter."
The pair's romance begins when Maisie offers to go Christmas shopping with Ryan.
The source added: "They give in to their feelings. But they'll feel sick and betrayed when they realise all their similarities are down to genes and not chemistry."
The storyline will lead up to Maxwell's exit from the soap in January.
