Where to Watch My Mom's New Boyfriend (2008)

His mom is dating his suspect. Let the surveillance begin.

After several years away, FBI agent Henry Durand returns to find his mother, Marty, a much different person: Having long mourned for Henry's father, she is now embracing single life. One day, while Marty, Henry and his new fiancée, Emily, are out for a walk, they meet Tommy, a mysterious stranger with whom Marty then becomes involved. However, through his FBI contacts, Henry learns that Tommy is suspected of being an art thief. As a young federal agent, Henry is given a difficult assignment: spy on his mother and her boyfriend who is suspected of leading a gang of art thieves.