The actor, who plays Anthony Moon in the BBC One soap, was first reported to be dating McGarty (Whitney Dean) earlier this month, when the pair were spotted together at co-star John Partridge's wedding.
He has since confirmed the romance but insisted that the couple don't publicly display their affections while at work.
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"When we're on set we try and keep it as professional as possible. There's no sneaking off and kissing," Lapinskas told The People.
Tony Discipline, who plays Lapinskas's on-screen brother Tyler, is dating fellow EastEnders star Jacqueline Jossa (Lauren Branning).
Speaking of their relationships being in the public eye since joining the show, Discipline recently explained: "It's completely different to what we're used to. People writing about your private life is strange and something we're getting used to."
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