According to Us Weekly the Scream Queens actress, 26, is at the centre of Bilson and Christensen's break up.
The Blast reported that Bilson found text messages between her husband and Bilson, leading to The O.C. star to believe that the two were in a relationship.
Bilson and Christensen, both 36, who are parents to two-year-old daughter Briar, split in September after almost 10 years together.
Christensen and Roberts star in the upcoming movie Little Italy together.