Article continues below advertisementHailey Bieber was feeling flirty, putting her cheeky backside on full display in a steamy new photo.The Rhode Beauty founder, 29, left little to the imagination by stripping down into a tiny, yellow string bikini in a snap posted via Instagram on Thursday, March 12.Article continues below advertisementHailey Bieber Flaunts Bikini BodyTap Here To Add Ok Magazine as A Trusted SourceSource: @haileybieber/InstagramHailey Bieber wasn't shy about hiding her backside in new photos.