© Rex Features
The 21-year-old actor got engaged to Taylor-Wood in 2009, and the couple welcomed their first child together last year, naming her Wylda Rae.
The couple will now become parents again after announcing that 44-year-old Taylor-Wood, who also has two daughters from her marriage to Jay Jopling, is pregnant.
She has spoken of Johnson's desire to be a father in the past, saying: "Aaron, almost before anything started between us, said he wanted kids. He was very clear about wanting a family.
"We hardly go out now, it's just us. Aaron has brought a set of values I didn't even know I was looking for - family values."
Earlier this year, Johnson was nominated for 'Best Actor' at the 2011 Jameson Empire Awards for his role in Kick Ass.
