Things have grown ugly between Briana Jungwirth and Louis Tomlinson.
And also between Briana Jungwirth and Danielle Campbell, the singer's serious girlfriend.
As previously reported, the One Direction singer and Jungwirth welcomed their first child into the world this past January.
His name is Freddie and he's very cute.
Tomlinson and Jungwirth were not a couple at the time the baby was born, having only enjoyed a brief romantic interlude last year that accidently led to a life being created.
But the two appeared to be on good terms and Tomlinson was intent on being a key part of Freddie's universe.
At the time they met Freddie, Tomlinson and Jungwirth did not have a custody or child support agreement in place, although the singer quickly agreed to pay his baby mama $15,000 per month and grant her physical custody of the boy.
However, a custody battle has since ensured because Tomlinson claims Jungwirth isn't letting him see his son.
Fast forward Wednesday of this week, however, and Tomlinson apparently having been given a chance to chill with the six-month old.
The only problem, in Jungwirth's eyes? He did so while also spending time with Campbell in Malibu.
"You can pretend all you want but you will NEVER be my baby son's mother," Jungwirth Tweeted after seeing a picture of the actress holding Freddie.
She didn't mention Campbell by name, but it was very clear what Briana was talking about.
It's understandable that Jungwirth may be troubled by the sight of another young woman holding her baby, but this is obviously unfair.
We doubt Campbell is trying to be anyone's mother. She's just being nice to her boyfriend's baby.
The incessant paparazzi butting into the lives of Tomlinson and his son has been so much of an issue that Louis was forced to ask for privacy in a statement earlier this month.
"The persistent and increasing levels of paparazzi and media intrusions into Freddie's life of late are not only posing potential security issues but are also crucially invading the privacy to which Freddie is undoubtedly entitled as a child," the statement read.
"The levels of paparazzi attention on Freddie are intolerable and completely unjustifiable.
"Louis appreciates, respects and values his relationship with the media and we hope he and his son are afforded the same respect on this matter."
The handsome singer has filed for joint physical and legal custody of Freddie, who is pictured above with Jungwirth.
For this sake, let's hope this all gets work out on friendly terms.