Not only did Lindsay Lohan deny that she had ever been romantic with Jax Taylor, she claimed she'd never even met him.

The Vanderpump Rules star is now calling Lohan a flat out 'liar' on Twitter in a post addressing the rumors on Thursday.

Back in 2015, Jax had revealed that he'd once had a tryst with the Mean Girls star on Watch What Happens Live - which Lindsay said didn't happen.

Liar liar: Jax Taylor accused Lindsay Lohan of being a liar in a tweet after she denied their rumored hook up on Thursday

'Not that I care, it was over 10 years ago and I am happily engaged,' Jax tweeted Thursday. 'But She's a liar, my two friends who have nothing to gain, were with me the whole night.'

Adding: 'That's all I will say on this. So you are lying darlin.'

Jax added a screen shot from what appeared to be a text conversation with one of the friends who purportedly was with him on the alleged night.

'B******t. Trav and I were w you when we went to her condo and she just got out of rehab. Lmao,' a friend named James wrote.

Not true: During an episode of WWHL this week, Lindsay was asked about her rumored tryst with the Vanderpump Rules star and said she'd never even met him

Clapping back: Jax didn't let Lindsay's denial stand and took to Twitter to say his piece

Part of the rest of the message the James sent was redacted by the Rules star.

Jax responded, 'I know, I don't care. She was the crazy house for how many years and didn't even know her own name you think she remembers who he hooked up with?'

'Exactly,' his friend responded in the text conversation. 'She was asking trav to get Lamar and he was like didn't you just get out of rehab??? Hahahaha'

Back up: The Bravo star even tried to provide some proof he was telling the truth

He said, she said: Both Jax and Lindsay are calling each other out for lying about the alleged romantic romp

It's unclear what or who 'Lamar' is or whether it was just an autocorrect fail.

During an appearance on the same Andy Cohen late night show this week, Lindsay played a round of Plead The Fifth and was asked about the rumored romp by a very special guest.

'Jax Taylor revealed on Watch What Happens Live that he once hooked up with you,' asked Lisa Vanderpump. 'How would you describe Jax as a lover in three words?'

'Not that I care, it was over 10 years ago and I am happily engaged,' Jax tweeted Thursday. 'But She's a liar, my two friends who have nothing to gain, were with me the whole night. That's all I will say on this. So you are lying darlin.'

Back up: Jax added a screen shot from what appeared to be a text conversation with one of the friends who purportedly was with him on the alleged night

Real Housewives: Lisa Vanderpump made an appearance on the Bravo talk show to ask Lindsay about the rumored hook up

The question elicited shocked laughter from the ginger haired star who denied the whole thing.

'Lisa, I love you, but I've never even met him.'

Flabbergast, Cohen asked: 'Really?'

'Really,' she definitively said.

'Maybe he met, like Annie or Hallie,' Lohan joked referring to her twin characters from The Parent Trap.

Shocked: 'Lisa, I love you, but I've never even met him.'

Say what? Andy Cohen was gobsmacked that the rumor appeared to be false

Cohen questioned: 'You're calling Jax Taylor a liar?' 'Yes,' Lindsay said.

Cohen questioned: 'You're calling Jax Taylor a liar?'

'Yes,' Lindsay said.

Andy joked that it wouldn't 'be the first time' anyone had accused Taylor of not being truthful.

Jax recently got engaged to Brittany Cartwright after previously cheating on her.