The Big Brother VIP star went on to say that, growing up, his sister got access to "the best schools, acting class, college, auditions".
"So, it’s OK for her to do it, but God forbid anybody in the Markle family does it?" Thomas questioned, adding that the opportunity to go on BB VIP was "incredible" and he "wouldn't trade that in for anything".
"Meghan's PR team has continuously bad mouthed the entire Markle family and I have a right to defend myself and my family on her vicious attacks in the media – so I just have to put that out there so that everybody gets a clear understanding of what’s fair and what’s not fair."
This, of course, isn't the first time Thomas has spoken about Megan. Just last week, the reality star shared details about his and his sister's upbringing to Nova's Fitzy and Wippa while in the Big Brother hotel.
“I was 15 when she was born so I fed her, babysat just the normal family stuff, but I grew up in a divided home my parents split up when I was really young as well," Thomas explained, adding, "My Dad made sure people got together for the holidays and the important things."
Asked if he's ever had any correspondence with Prince Harry, Thomas revealed, “No, not me, my father did. My Dad doesn’t approve of him."
"My father says that he couldn’t even protect those chickens in their backyard if he needed to."
Thomas added that Meghan "kind of knew what she was getting into" when she entered the royal family.
"If you got a job and you got paid 4 million dollars a year salary to go bow and curtsey and take pictures and do some charity work here, some charity work there, I mean that’s about the highest pedestal you can get to. Do your job and not gripe about it.”
Meghan, on the other hand, hasn't said much recently about her relationship with Thomas or her other half-sibling, Samantha. But in her infamous interview with Oprah, she made it clear that she didn't count herself as close to them.
"I grew up as an only child, which everyone who grew up around me knows, and I wished I had siblings. I would have loved to have had siblings - that's why I'm so excited to be pregnant so that Archie has someone," the former Suits star explained at the time.