Fact: Few pop stars are hotter or sexier than Rihanna. She doesn’t need to prove it, but her horde of fans (especially the boys) won’t complain when she posts a super sexy topless photo on her Twitter account. However, it’s not X-rated, since she covers the “girls” with her strategically placed arm. Dare we say that the image is artfully and impulsively sexy? It’s certainly not vulgar.