The 'Real Housewives of Beverly Hills' star set up a profile on the social networking site to track her ex-husband, Eddie Cibrian, and his 31-year-old wife, who tied the knot in 2011 after embarking on an affair on the set of the movie 'Northern Lights' that led to the breakdown of both of their first marriages in 2009.
In the first chapter of her upcoming second book, 'Drinking & Dating: P.S. Social Media Is Ruining Romance,' Brandi wrote: ''When I first discovered the benefits of technology and social media. I used it to obsess about my husband, his future wife, and our children throughout the breakup and divorce.''
Brandi, 41, has had a long-running public feud with 'Spitfire' hitmaker LeAnn, who she refers to as a ''c**try singer,'' but the pair were thought to have buried the hatchet last year when the singer sent the reality TV star flowers for Mother's Day in May.
Brandi, who has sons, Jake, 10, and Mason, six, with Eddie, previously predicted her acrimonious relationship with LeAnn would drastically improve if the singer got pregnant because it would help her to learn boundaries as a mother and stepmother.
She said: ''Hopefully, they'll have a child of their own and she'll understand better what a proper boundary is for a stepmother and a mother.''
His new album Underneath It All is out now.