LENNON KID WAS FLACK'S HEAVEN!

ICONIC singer Roberta Flack died childless, but sources say the Killing Me Softly songbird was secretly a second mother to John Lennon's son Sean after the Beatles great's 1980 murder just outside his Manhattan apartment building.

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The 88-year-old You Are My Heaven legend - who died from cardiac arrest in February following a number of strokes that robbed her of the ability to sing - had moved into the famed Dakota where she was a next-door neighbor to the Lennons.

Sean, now 49, recalls: "I was very blessed that I grew up with the coolest neighbor in the world - we used to call her Aunt Roberta, and we were very close."