Lily Allen says James Corden used to be very friendly with her before he hit the big time — so much so, in fact, that he came off as a little desperate … according to her anyway.

The British singer opened up about her history with James on her “Miss Me?” podcast … claiming the comedian used to beg to hang out with her and her friends back in the day.

Lily says it all started when James came on her old chat show way back in 2008 … in her recollection, James was super flirty and they kinda became loose friends.

From there, Lily says she introduced James to some of her pals and they hung out for a week or so … and she goes on to claim James felt she was leading him on but is adamant that was never the case.

Lily’s podcast co-host, Miquita Oliver, remembers the James Corden days too … and they make it sound like James was trying to climb the social ladder back then.

As Lily describes it, James was more of a “beg friend” than a real pal … describing the term as British slang for someone who begs to hang out with folks who aren’t all that interested.

James has since risen to major fame, and Lily says his begging days are long gone.