Coronation Street star Ellie Leach says there'll be hell to pay when her character Faye Windass finds out about her brother's murderous ways.
Gary is the biological son of Faye's adoptive mother Anna, and has always been protective of his little sister.
But how will she react when she finds out what he's been up to lately?
Speaking exclusively to Mirror Online at Nickelodeon's Slimefest at Blackpool Pleasure Beach, she said: "You know what, I think she's going to be absolutely mortified. She hasn't really seen him much lately but she's going to be so angry when she finds out what he's been doing.
"I hope she gives him a good telling off."
Gary, played by Mikey North, has been heading down a dark path ever since he got involved with loan shark Rick Neelan.
Gary owed Rick a lot of money and they ended up fighting to the death.
After murdering Rick, Gary took over his loan business and has been involved in some dodgy dealings and has been handing out the beatings.
He's also sparked up a scam where he's bought the knicker factory, making one of his customers pose as the investor so nobody knows it's him.
Gary has also been unmasked as the culprit behind the Underworld roof collapse which killed Rana Habeeb on her wedding day and saw the business closed down in the first place.
Ellie, 18, recently completed her studies at college and is concentrating on her work with the ITV soap.
She said: "I've just finished college now and all my friends have gone off to uni but I'm not because of work and everything it's not really something I'd like to do."
Meanwhile, Gary has been revealed as Maria Connor's new love interest.
Actress Samia Longchambon told us: "She's so unlucky in love, it just never works out. You know whenever she's happy that it's not going to last.
"This current storyline and who she gets together with next, I think I can say it's Gary, it's been teased, and that's going to be full of twists and turns, and you just know that's not going to end well either.
"Let's let her be happy for a little bit though."
She added: "I'm really excited to do it. We've started doing it a little bit now and it's really good fun and it's great working with Mikey as well."
* Coronation Street airs Mondays, Wednesdays and Fridays on ITV