You know how it is.
That skimpy swimsuit looked great in the changing room, but it's another matter when it comes into contact with a wave.
Did this lady give her new two-piece a proper pre-holiday road test?
It appears not.
Tsk tsk Penelope Cruz.
How many blushes she would have saved if she'd just bunged her bikini on in the shower at home one morning and jumped up and down a bit...
Its tendency to inch skywards would have become blindingly obvious.
We have to hand it to her though, Pen didn't let a bit of cup creepage hold her back as she larked around on a Caribbean beach.
As our gallery reveals, that unreliable bikini was subjected to more than just a half-hearted splash in the sea.
But hey, Penelope can just blame her wandering bra top on the impressive proportions of her much-envied boobs.
She could even just blame it on the shrinking effects of sea water.
But then, she is on holiday in the sizzling Caribbean in the greyest month of January.
So when it comes to the embarrassment of sporting such ill-fitting beachwear, we bet she couldn't give a fig.
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