Before Brian Austin Green allegedly cut his son out of his life, the two had a close relationship
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Brian Austin Green‘s relationship with his oldest son wasn’t always strained.

Earlier this week, Green’s ex Vanessa Marcil shared an emotional message to Instagram, in which she claimed that their only child together — 16-year-old Kassius Lijah — was cut out of Green and wife Megan Fox‘s life five years ago.

But before Green and his son allegedly became estranged, the two had a close relationship.

Vanessa Marcil and Kassius
| Credit: Vanessa Marcil/Instagram

When Green tied the knot with Fox in 2010, Kass, then 8, not only served as his father’s best man, but he was also the only guest invited to the intimate Hawaii wedding ceremony.

The wedding came four years after Marcil claimed Green and Fox tried to get full custody of Kass in 2006.

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Megan Fox and Brian Austin Green
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“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,” Marcil wrote an emotional Instagram on Sunday. “They lost that case & a civil case asking me for 200,000.”

Despite the legal drama, Marcil said she never challenged Green’s right to 50/50 custody.

“I never spoke publicly in order to protect my then young son from paparazzi that used to follow him & terrify him,” she continued. “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.”

According to the actress, Green, 45, and Fox, 32, “decided to completely cut Kass out of their lives” with their three sons: Journey River, 2, Bodhi Ransom, 4½, and Noah Shannon, 6.

“Kass has never met his youngest brother and is not allowed to know where his bio father, stepmother and three younger brothers live,” wrote Marcil, 50. “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.”

Green and Marcil started dating in the late 1990s after meeting on the set of Beverly Hills, 90210. (He played David Silver for all 10 seasons, and she joined the cast as Gina Kincaid in season 9.)

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Vanessa Marcil and Brian Austin Green
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After several years of dating, the two got engaged in the summer of 2001 and welcomed Kass on March 30, 2002. As PEOPLE reported at the time, they planned to wed that summer.

While it’s unclear why they split, Green and Marcil called it quits shortly after Kassius’ birth, in 2003.

Green began dating Fox the next year.