Latest "The Real Housewives of Atlanta" updates claim that Phaedra Parks and Apollo Nida's relationship (or at least what's left of it) is going downhill. Fast.

A source close to Phaedra told HollywoodLife.com exclusively that Parks' estranged husband has sent her a very rude letter after the RHOA star would not accept his calls.

"He's so childish," the source said. "She [Parks] said, 'He tried to get me together by telling me what he thought about me and numbering each pathetic insult.'"

"Phaedra said that Apollo called her a b*tch, selfish, fat, conceited, and a wife that ain't loyal.

"He even told her that if it wasn't for their kids, he wouldn't care if he saw her fat ass ever again. He said it to her in a letter just like that," the source continued.

Parks and Nida have reportedly called it quits, citing Parks' unwillingness to shoulder a costly marriage once Nida finally goes behind bars as one of the reasons for the split.

Meanwhile, can Nida's accusation of Parks not being a loyal wife be true?

New "The Real Housewives of Atlanta" rumors surfaced claiming Parks might not be the victim at all. In fact, she might have been unfaithful to her husband. As Celeb Dirty Laundry reported:

"There are some pretty explosive claims coming from the The Real Housewives of Atlanta set these days, with the most recent being that Phaedra Parks is allegedly cheating on Apollo Nida and dating a rich African man she has affectionately coined "Mr. Chocolate." In the recently released super trailer for season 7 (which airs this November 9 on Bravo), we catch a glimpse of Cynthia Bailey accusing Phaedra of the adulterous affair. This happens immediately after viewing a clip of Phaedra's (now incarcerated) husband Apollo Nida confessing he thinks his wife is cheating to Cynthia's husband Peter Thomas."

Stay tuned for more "The Real Housewives of Atlanta" news here.