Vanessa Marcil has urged Brian Austin Green to put "kids first" after accusing him of cutting their son out of his life.

Megan Fox and Brian Austin Green

Megan Fox and Brian Austin Green

The 'Las Vegas' actress has 16-year-old Kassius with her former partner but she claims the 'Beverly Hills 90210' actor and his wife Megan Fox - who have Noah, six, Bodhi, four, and two-year-old Journey together - have only seen the teenager a handful of times in the last five years.

She shared a screenshot of one of her own comments on Instagram which read: "They have been at the same wedding, same resort and same play a few times in passing and a few 60 minute lunches. That is it."

She then captioned the post: "From yesterday also so calm tf down guys. The truth is the truth and it IS needed for healing after 15 years. Love to all parents. Moms and dads. Let's put our kids first.(sic)"

The 50-year-old star's post came a few days after she claimed Kassius had never met his youngest half brother and doesn't even know where his dad lives with his family.

She wrote on Instagram: "5 years ago on their own they 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. He has only seen his dad in passing in public places.(sic)"

Vanessa also went into detail about the custody battle she went through with the 45-year-old actor and his 32-year-old spouse, explaining they initially requested full custody but lost their bid and were slammed by the judge.

She wrote: "12 years ago I was served legal papers and then spent 8 years+ defending myself and my son in custody court in response to his father & his stepmother trying to get full custody(that means I would have seen my son four days a month) and then asking me to pay them child support.

"They lost that case & a civil case asking me for 200,000. I never spoke publicly in order to protect my then young son from paparazzi that used to follow him & terrify him.

"I had also never asked for child support of any kind and had never tried to take time away from Kass' dad seeing him. Ever. In the end they lost all of these court cases. The judge called them all "Frivolous".

"They always had 50% custody and still did when court ended as I had and have NEVER asked for full custody. (sic)"

She urged divorced parents to work together for the sake of their children.

She concluded: "Custody cases hurt the children only and the truth shall set us all free. Put the kids first you guys. There shouldn't be a "more important parent" kids love both parents equally no matter what either parent's struggles may be. Kass has been truly heartbroken since being cut out of his other families lives with NO explanation. Let's do better for our kids.(sic)"