One or two images of Selena Gomez in a see-through swim suit with Cara Delevingne are floating around as part of celebgate. Selena's people have as yet made no statement. However as I am a complete whore for celebrity news I can tell you with some certainty that they are as fake as this plastic plant:
The photos of Selena are from a little while ago where she was on a boat with Cara wearing a white - and in completely no way see-through - swimsuit. I'd point you to where you can find the originals but their freaking server has crashed under all the hits for today's images.
Put it away fappers and move on.