The 30-year-old actor, who is best known for playing Ryan Molloy in Eastenders, was photographed leaving his two-bedroom property in Sutton with a bin liner and no wedding ring yesterday.
At the weekend, McDermott apologised to wife Michelle Edwards and their newborn baby daughter for the "betrayal" of having a one-night stand with 16-year-old Chloe Peebles in a hotel room two weeks ago.
According to The Sun, McDermott arrived at the house with an older woman - believed to be his mum Sharon - stayed inside for three hours and then left carrying what appeared to be his belongings. There was no sign of 29-year-old Edwards.
When asked how he was, the soap star just shook his head.