Last month, show bosses announced that former Coronation Street star Jeremy Sheffield had been cast as Patrick for upcoming scenes which see Dodger track down his long-lost dad.
When Dodger finally gets Patrick's address in a future episode, he heads off to pay him a visit - bringing along Darren Osborne (Ashley Taylor Dawson) for moral support.
Mac told All About Soap: "Darren suggests he goes to visit Patrick and pretend to be gathering information for the census! Dodger's shocked when he first sees Patrick's house - it's huge with expensive cars on the driveway. It's the opposite to the place where Dodger grew up.
"As Dodger and Darren arrive at the house, they see a girl who later turns out to be Patrick's daughter Sienna. When Dodger meets Patrick, he's struck by what a decent, charming, handsome bloke he is. But when Dodger reveals he's his son, he doesn't get the reaction he was hoping."
The actor continued: "[Patrick is] adamant that his son Mark - which is Dodger's real name - is dead, because that's what Dodger's mum Anne told him years ago. It's an afternoon of bombshells because after Dodger proves his real identity, Patrick reveals Sienna is his twin sister."
Hollyoaks first announced the twin twist in early October and actress Anna Passey is playing the role of Sienna.
Asked where the story heads next, Mac explained: "You'll be seeing a lot more of Patrick and Sienna in the village in the next few weeks, as they try to build a relationship with Dodger. Suddenly Dodger has two families, so it'll be fun to see how it all plays out."
He added: "You're going to see him pulled in about a hundred different directions in terms of family. It's going to be a whirlwind for him - horrible, but very exciting."
Hollyoaks airs weeknights at 6.30pm on Channel 4, with first look screenings at 7pm on E4. Get the Inside Soap magazine on your iPhone or iPad