It began when the 54-year-old actress answered a fan’s inquiry about whether co-parenting has been difficult.
Taking to her Instagram Stories she replied, ‘We didn’t and don’t co-parent. I raised my son alone.’
Along with her answer she shared a throwback image of her and Kassius, now 20, from when he was a little boy.
The Beverly Hills 90210 actor, 49, screenshot the post and wrote, ‘Megan and I [busted] our a**es to give Kass a well-rounded childhood [because] his mom was rarely there.’
Clapback: Brian Austin Green praised his ex-wife Megan Fox while disputing his ex-girlfriend Vanessa Marcil’s claim that she raised their son Kassius by herself in an Instagram story
What happened: The spat began when the 54-year-old actress answered a fan’s inquiry about whether co-parenting has been difficult; (L) pictured with Vanessa in 2000; (R) pictured with Megan in 2014
He began the post by stating, ‘So, I can’t tell you how frustrating it is to read continued lies from a 50+ year old woman on social media like she is still in high school.’
The disgruntled father-of-five continued, ‘She has never in her life been someone to walk the walk.’
Speaking to his 710,000 followers on the platform he added, ‘Talk is cheap. Megan and I [busted] our a**es to give Kass a well-rounded childhood [because] his mom was rarely there.
‘I’m assuming that’s why she posts so much of him now. When will she just GO AWAY,’ he added with a laughing-out-crying emoji.
It’s not the first time the former couple has taken their family drama to the public.
In October of last year Brian put his ex Vanessa on blast after learning about her alleged version of their custody battle over their son.
‘I just heard that my ex was claiming I spent years taking her to court and asking for child support. How was I the Respondent then???’ he posted to Instagram.
Green shared a portion of an alleged legal document which showed Marcil labeled as the ‘petitioner’ and himself as the ‘respondent’ in order to back up his claims.
Like father, like son: Brian’s firstborn child Kassius, 20, recently worked alongside him on a western film called Rufus
Bringing receipts: Last year Brian put his ex Vanessa on blast after learning about her alleged version of their custody battle over their now 20-year-old son Kassius
Brian also posted photos showing his repaired relationship with son Kassius, following claims made by Vanessa years ago that he had cut his son out of his life.
He posted two snaps of them filming a movie called Rufus, and called it a ‘great experience.’
‘Working with Kass on a movie titled “Rufus” Such a great experience!!!’ he captioned one shot. A second shot of the father-son duo on set was captioned: ‘Another one of Kass and I from the set of Rufus.’
In 2018, Vanessa alleged Brian had cut off all contact with their son five years prior after failing to get full custody of their child during a protracted legal battle.
In an Instagram post, the actress alleged that Green and his then-wife Megan Fox ‘decided to completely cut Kass out of their lives and his younger brothers’ lives. Kass has never met his youngest brother and is not allowed to know where his bio father, stepmother and three younger brothers live.’
But in 2020, Marcil suggested Green had repaired his relationship with Kassius, who visited his father on the set of BH90210 a year earlier.
‘My son was finally invited back into his dad’s life and was able to finally meet his youngest brother and finally see his other two siblings again,’ she posted to Instagram. ‘My son is also an incredible big brother.’
Marcil and Green, who starred together on Beverly Hills 90210 from 1998 to 2000, never married. They welcomed Kassius in March 2002.
Marcil, whose first marriage was to actor Corey Feldman from 1989 to 1993, went on to tie the knot for a second time with actor Carmine Giovinazzo in 2010. She filed for divorce two years later.
Green has since divorced Megan Fox, who is now engaged to music artist Machine Gun Kelly, and they share Noah, ten, Bodhi, eight, and Journey, six. In June, Green welcomed a son named Zane with girlfriend Sharna Burgess.
Big family: Green shares Noah, ten, Bodhi, eight, and Journey, six with ex-wife Megan and in June he welcomed a son named Zane with girlfriend Sharna Burgess