The pair first fell out when Eddie Cibrian, 39, left his then wife Brandi in 2009 for his current wife LeAnn and despite publicly offering her support to the singer when she went into rehab earlier this year.
Brandi lashed out at LeAnn again in new Twitter rant for referring to her step-sons as her own and hinted that LeAnn's marriage is in trouble.
The singer posted a message on her profile on 30 November while on her way to Oregon with Eddie and his sons Jake, five, and Mason, nine, that irked their mother Brandi.
LeAnn took to her Twitter page and wrote:
Flying out with my boys in a few hrs. Love that it's a family tour weekend. It's always more fun when they are with me.
— LeAnn Rimes Cibrian (@leannrimes) November 30, 2012
Upon seeing LeAnn's tweet, The Real Housewives of Beverly Hills star responded by tweeting:
Someone is trying 2 get under my skin by calling MY children "her boys"Sooo transparent!They R MY boys, Eddie Boys and ur step-sons... 4 now
— Brandi Glanville (@BrandiGlanville) December 1, 2012
She later wrote: "Im trying not to tweet about something I just saw.... Breathe (sic)" Minutes later she made another post saying: "Im taking a moment from twitter to breathe and punch some pillow (sic)."
LeAnn refused to hit back at Brandi and simply wrote: "I'm so grateful for amazing positivity and positive people in my life."
The 40-year-old reality TV star previously admitted relations between her and LeAnn have been strained recently.
"Right now [our relationship is] not amazing. I'm just saying... and I'll leave it at that," Brandi said in a recent interview.