Not since Katherine Heigl upped from her deckchair and sauntered her splendid figure towards the pool in My Father The Hero did perfectly decent human beings feel such terrifying guilt.

Heigl was just 14 when her she first popped up on the man radar in 1994 – these are the facts – and now she’s back to elicit more admiration from her long-standing fan base.

She’s starring opposite Seth Rogen in an inspiring story of a one-night stand that morphs into the unlikely but charming tale of babies and love and stuff.

Their relationship, if haphazardly conceived, is expertly exploited by director Judd Apatow. She's the raunchy buddy, he's the clown who ended up in bed with her after drinking lots of sambuca. Never has the rom-com seemed so appealing.

Knocked Up hits screens August 24.

And here's why she's worth watching: