Chris Watts, the killer who was documented in Netflix's hugely popular true crime documentary American Murder: The Family Next Door, has spent his 36th birthday behind bars.
However, Watts - currently serving a life sentence for the 2018 murders of wife Shanann, who was 15 weeks pregnant, and their daughters Bella, four, and Celeste, three - won't be celebrating with anyone.
According to People, not even his inmates at maximum-security Wisconsin prison Dodge Correctional Institution have any time for him.
The publication cites a source 'who regularly speaks to him'. They said: "No one wants anything to do with him.
"He's on the lowest social tier of the entire prison. He's in protective custody because if he's around other inmates, he'd be in real danger. He's an outcast, even among criminals."
Watts turned 36 two days ago and seemingly goes days without talking to anyone, with fellow prisoners and guards snubbing him.
"He's probably the most hated man in that prison, because he killed children," the source said.
"There's a definite pecking order in jail, and someone who hurts or kills kids is at the very bottom."
Watts has already been moved once during his sentence, due to security fears at his previous location in Colorado.
However, he's clearly no more popular in Wisconsin.
Instead, Watts spends most of his time corresponding with the few pen pals he has from the outside.
"He'll write [to] his penpals this season, and they're sending him notes, as well," the source said.
"It's literally all he can do at this point."
Watts has apparently planned to appeal his sentence - which totals at five life sentences, including three consecutive and two concurrent - without the possibility of parole.
He hasn't filed any paperwork to do so, though, and the source said: "He's a young guy, only 36, so he could live like this for the next 50 years.
"It's probably a fate worse than death."
The Watts family murders became global knowledge with the release of the Netflix documentary in September of last year.
It detailed the disappearance of Watts' wife and his young daughters, with the oddly calm Chris reporting the case himself.
As the story unravelled though, it soon became clear that his family had been killed - and he'd been the culprit.
Keen to start a new life with a woman he'd been having an affair with, Watts had murdered his family before burying his wife in a shallow grave at the Anardarko Petroleum site, before disposing of his children's bodies in one of the petrol tanks itself.
Initially, Watts had claimed that it was Shannan who had killed the kids and so he had strangled her in a rage, before he ultimately confessed to everything.
It was reported that 52 million households had started the documentary series in the first month of its release.
It's since been claimed that Watts' mistress, Nichol Kessinger, may be one of his pen pals - having reportedly been in touch with him since he moved to Wisconsin.
"He told me she said that she needed to speak to him to clear some things up," inmate David Carter told The Daily Mail.
"He wouldn't tell me exactly what she had said."
Featured Image Credit: Netflix