The Slave 4 U singer, 40, started her controversial post by sharing how happy she is in her "new adorable neighborhood" after buying an $11.8 million mansion in Calabasas, not too far from where K-Fed, 44, resides with their two teenage sons, Sean and Jayden.
"It's beautiful, but I miss my other house for some reason," Spears continued. "It's hard for me to let go of things I truly love ... like my kids."
She then vented about her recent dispute with Federline. "That situation should have 100 percent been dealt with privately and definitely not online!!!" Spears went on.
Her post came after his attorney Mark Kaplan claimed the former couple's two sons miss their grandfather Jamie Spears and are in no rush to reunite with their mother. It also came as K-Fed is set to spill shocking details in a tell-all interview airing later this month.
Spears noted that a British TV network claimed their stepmom's "goal is to keep the children away from all of the controversy and trauma in my home," stating that her abode is filled with love and blessings from the people she lets in and out.
The Grammy-winning artist highlighted that she always looks forward to seeing her kids weekly, but the time spent together has become less frequent.
"I know that teenagers are just hard to deal with at that age," she continued.
Spears admitted she used to not speak up because "if I say something argumentative like I did with a dance move saying no to it, I got sent to that place for four months!"
She then appeared to cryptically call out her ex, writing, "So as much of you watch, what he refers to his family as the PERFECT BRADY BUNCH family ... I can guarantee you, that house has more weed than Ludacris, 50 Cent, Jay Z and Puff Daddy combined!!!!"
Fans didn't take kindly to the references or to her use of the word "peckerhead" in the following line, blasting the songstress for going too far.
She fired back, "He wants to bring up my past with that bald-headed peckerhead face Kaplan and circle back to that hard time in my life!! That was almost 20 years ago."
On Wednesday, K-Fed had Spears supporters up in arms when he leaked old videos taken by Sean, 16, and Jayden, 15, showing the trio in a heated argument.
"I can not sit back and let my sons be accused in this way after what they've been through," Federline captioned the since-deleted post.
"As much as it hurts us, we decided as a family to post these videos the boys took when they were 11 & 12. This isn't even the worst of it. The lies have to stop. I hope our kids grow up to be better than this. #NeverFearTruth."