A source tells ET that the personal trainer 'finally hit a breaking point' with Britney's dad, Jamie Spears.
In a message shared to Instagram Stories on Tuesday, the personal trainer addressed Britney's ongoing conservatorship battle, which was examined in The New York Times' unauthorized Framing Britney Spears documentary that premiered last week.
"Now it's important for people to understand that I have zero respect for someone trying to control our relationship and constantly throwing obstacles in our way. In my opinion Jamie is a total d**k," Sam, who's originally from Tehran, Iran, wrote. "I won't be going into detail because I've always respected our privacy but at the same time I didn't come to this country to not be able to express my opinion and freedom."
While ET's source says Britney's team "isn't surprised at all" that Sam is furious over the legal constraints his girlfriend has been under since 2008, they are surprised that he "vocalized his feelings in the way he did."
"He has never been the type to speak out publicly in any negative way. Sam has always played ball and followed Jamie's lead, but he's finally hit a breaking point," the source says. "It seems like the documentary and the recent support coming from Britney's fans has given him the strength he needed to finally speak out."
"Sam has been faithful, loyal and by Britney's side through many difficult ups and downs," adds the source. "He feels like Jamie is far too controlling and adds a layer of trouble to their relationship. In Sam's eyes, there are far too many restrictions."
Sam wants Britney to "finally be free of the conservatorship," the source says, adding that he's "one of the few people who doesn't need a chaperone to be around her."
"There are restrictions on who she can see, and while Jamie lets Sam be with her, she has limited access to people outside her staff and legal team," the source says. "Jamie sees the men in Britney's life as a possible threat to her career and a distraction. He has never treated Sam as an ally, which has backfired on his relationship with his daughter."
"Jamie worries about her well-being and her spending sprees. He worries about her taking care of herself and her health," the source continues. "Those closest to this situation know Jamie has her best interest at heart and her team believes Jamie's involvement is very much needed but worry he has alienated himself unnecessarily. At this point, it would be beneficial for Jamie and Sam to work out their differences, which after everything that has happened is easier said than done."
Sam, who met Britney when he was cast in her 2016 music video for "Slumber Party," told ET in a statement earlier this week that he's looking forward to their future together.
"I have always wanted nothing but the best for my better half, and will continue to support her following her dreams and creating the future she wants and deserves," the statement read. "I am thankful for all of the love and support she is receiving from her fans all over the world, and I am looking forward to a normal, amazing future together."
Meanwhile, it appears Britney seemingly reacted to the new documentary on her own Instagram account. On Tuesday, the 39-year-old singer posted a video of herself performing "Toxic" three years ago.
"I'll always love being on stage...but I am taking the time to learn and be a normal person," she captioned it. "I love simply enjoying the basics of every day life !!!!"
"Each person has their story and their take on other people’s stories !!!! We all have so many different bright beautiful lives 🌹🌸🌷🌼!!!" she continued. "Remember, no matter what we think we know about a person's life it is nothing compared to the actual person living behind the lens 📷✨ !!!!"
Hear more in the video below.
Reporting By Adriane Schwartz
The New York Times Presents Framing Britney Spears is streaming on Hulu. Here's how to watch the documentary.