Explaining that the chat was not quite what it seemed, she wrote, "No, I wasn't horny for James cordon (sic) either, he came on to me in front of a studio audience, if I'd have shut him down, I would have been labeled cold or up myself or snobbish".
During the segment, Allen complimented Corden's "dazzling eyes", the actor returning with: "I don't think you know how lovely you are".
After some light banter, Allen quipped "just f**k me", adding: "That's how you get into a girl's trousers". Watch the cringe-inducing interview below.
But when a Twitter used sent Lily the clip on Thursday and accused her of being "horny" for James, she insisted that wasn't the case.
He admitted to "openly and blatently flirting" with her, saying: "I hadn't seen Lily since when I got a call asking if I'd go on her chatshow to promote the new series of "Gavin & Stacey".
A freakish new celebrity feud is unravelling itself on social media between Lily Allen and James Corden - and we have to say that it really makes no sense to us.
Piers tweeted a photo of Lily appearing to palm his crotch during a photoshoot, with the journalist quipping: "I preferred it when you just harassed me in the flesh". So she walked up the stairs with me padding behind, my mouth dry, my stomach churning, my hands sweating - I was all kinds of sexy.
The LDN singer claimed she'd been forced to hold back after a series of flirty remarks or she'd have been seen as "cold" or 'snobbish'.
He then admitted to realising it was "all in his mind", adding: "I'm glad that's all it was". I like Lily very much and know if push came to shove that night, I'd have been bad in bed.