3am: PARIS'S EYEFUL.

Byline: Kiki King, Eva Simpson & Caroline Hedley

NO wonder Paris Hilton is hiding behind those big white shades.

The socialite - who was snapped at Heathrow on her way back to LA - was clearly feeling the strain after a couple of wild nights out in London.

As well as celebrating her 25th birthday, the party girl had presented a Brit award and modelled for Julien Macdonald earlier this week - not to mention turning up at more Brit bashes than any other celeb.

When it comes to ligging, she's in a league of her own.

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MORNING AFTER: Paris heads back to LA and, below, out on the town' Pictures: DENNIS STONE and REX FEATURES