Spencer Pratt has savagely branded Lisa Kudrow "one of the worst humans I've ever met" in a TikTok video.
The Hills star Spencer, 39, made the revelation as he was quizzed by a fan on the social media platform.
In the video, the question from the fan appears in the top left corner, which reads: "Spence!! Tell us the rudest celebrity you've met!!"
In the clip, the reality star reveals: "Oh that's easy. Phoebe from Friends; hands down one of the worst humans I've ever come into contact with, by far."
Followers reacted to the footage with shock as one wrote: "What??? Noooooo".
Another added: "but wait I want the story behind this please", to which Spencer replied: "If this hit million plus views i will think about telling the story".
But others couldn't help but make a joke as one said: "are you sure you didnt meet regina phalange" and another suggested: "You must’ve met her twin sister Ursula cause it could’ve never been phoeb’s". [sic]
However, Real Housewives of New York City star Bethenny Frankel agreed with Spencer as she commented with: "That’s crazy. She was on my talk show and I had a crazy experience also".
Friends star Lisa, 59, appeared on Bethenny's talkshow in 2012.
Meanwhile, another follower commented: "Story? Maybe she was just having a bad day".
But, Spencer responded to insist: "It was a targeted attack".
The Mirror has contacted Lisa's representatives for comment.
Spencer is currently awaiting the arrival of his second child with his wife Heidi Montag.
The reality star met Heidi in a nightclub in West Hollywood in the mid 2000s before their romance became a focal point in reality show The Hills.
Spencer and Heidi eloped in 2008 to Mexico to tie the knot. However, trouble hit paradise in 2010 as the pair separated and nearly divorced.
But the pair worked through things and, seven years later, welcomed their first son Gunner Stone, now four, into the world.
Now Heidi is expecting the couple's second child, who is due in December, after struggling to conceive for years.
Sharing the news in June wit Us Weekly, Heidi said: "I couldn't be more excited. I don't know who I'm the most excited for — myself or Gunner or Spencer."
Heidi also discussed her long burning desire for a second child as she added: "I just felt like something was missing. I felt like a person was missing in our family that I had this intense love for."
"And I kept praying about it. I'm like, if I'm not meant to have another kid — because I had accepted that at this point — I just wanted to not have that desire so strongly and I just wasn't sure if it was going to happen or not. I just get so emotional about it," she added.
