Pierced nipple clips:
http://www.mostwantednude.com/pink.htm
http://www.huffingtonpost.com/2010/01/31/pinks-grammy-performance_n_443915.html
Pink shows pierced nipples
http://www.glamzilla.com/2010/03/11/pink-topless-photoshoot/
http://www.singerpictures.com/pink-pictures.html