On Wednesday, Blair — who was diagnosed with multiple sclerosis (MS) last year and now using a cane to walk — shared a photo of herself preparing to descend into the water. It was a big moment for the star as she has struggled with her mobility.
However, just as she planned to achieve the feat her 8-year-old son Arthur Saint pushed her off the edge.
“I sometimes doubt my child’s ethics. Preparing to dive. A very big deal for me. Instead, I felt a tiny hand on swimsuit and lost any coordination,” Blair, 47, captioned the post, which shows her going from perfect form to flailing into a belly flop.
“#Terror #PunkKid #PayBack is coming. Any ideas?” the Cruel Intentions star asked her fans.
Hours later, Blair revealed her revenge.
As payback, the star shared a photo of herself diving bottomless into the pool.
“Victory. I don’t give up. #BottomsUp 🐳 My boy is a #CrackUp @KidsArthurSaint.”
“You win,” producer Jamie Sullivan wrote in response to Blair’s post.
Aside from embarrassing each other, the mother-and-son duo has gone through a lot together this past year.
Since her diagnosis, Blair experiences daily ups and downs living with the chronic neurological disease, never knowing what to expect from her mind and body when she wakes up every morning.
Blair exclusively told PEOPLE she is honest with Arthur (his father is fashion designer Jason Bleick, whom Blair dated from 2010-2012) about her new challenges and is constantly impressed by his resilience.
“He’s had to endure a lot; he’s seen a lot,” Blair said, including watching her fall down stairs or rush to a bathroom if she’s feeling sick.
But Arthur doesn’t view his mom’s weaknesses negatively, she said. “He says, ‘Mommy’s not sick. Mommy’s brave.'”
The actress said she was recently surprised to learn that Arthur enjoys having her visit his school.
“He said, ‘I love when you come to school because you make the kids laugh and you answer all their questions,'” she recalled. Blair said she doesn’t shy away from explaining to the kids about why she “walks and talks funny.”
“I explain what’s happening and that my voice doesn’t hurt, and we have really decent exchanges,” she said. “I had no idea Arthur was proud of that. I thought ‘I’m probably an embarrassment,’ but to know I’m not was one of my proudest moments.”