The actor, who plays Ryan Malloy in the BBC One show, cheated on her in February with 16-year-old fan Chloe Peeble after meeting her in a nightclub.
Michelle, who has been with McDermott since they were teenagers and has a four-month-old daughter with him, initially kicked the soap star out, but has now decided to give him a second chance by moving into a new £300,000 home in Datchet, Berkshire, the Sunday Mirror reports.
A source told the paper: "It will take a long time before they are back to being the happy couple they were," adding that relations are currently "extremely strained".
McDermott said at the time of his infidelity: "I am so sorry to my wife, daughter and our family for this betrayal. I love my wife and family dearly and I'm distraught that my life is now in tatters due to a stupid mistake.
"I've no excuse for my actions but I had no idea the girl wasn't over 18 as we met in a nightclub. Either way, I've caused heartache to those I love most which I deeply regret. This was a one-off incident but I've let myself down as well as my wife and everyone who knows me."
Peeble revealed that McDermott was shocked when he discovered her age, but insisted that she did not want to be a home-wrecker.