Emma Watson worries people will see up her skirt on the red carpet.

The 'Bling Ring' actress has made a bit of a boob of herself at high-profile events in recent years - flashing her nipple tape and underwear on separate occasions because of her daring dress choices - and has learnt to suffer for fashion in order to avoid revealing too much.

She said: ''Getting ready for an event can feel like a lot of pressure. You have to consider, 'Will people see up my skirt? If a flash goes off, can you see through this?' So I'll do a test sitting, a test standing ... It's nerve-racking. People really scrutinize...

''On the red carpet, I'm usually in so much discomfort - my shoes are uncomfortable, I can't breathe in the dress. I don't compromise like that in my everyday style.''

The 23-year-old star is the latest celebrity to join forces with the Green Carpet Challenge, which works with top designers to create sustainable and ethically-sourced clothing, a cause which she strongly believes in.

Emma told The Edit magazine: ''Maybe there would be fewer problems if we were really conscious of where and how things were made. We don't support slave labour in this country, so we shouldn't support those conditions in other countries.

''I can't wrap my head around why ethical clothing is a speciality and not a base standard. Why is it special to have something you know wasn't made under terrible conditions by a 12-year-old girl for 20 pence an hour?''