Justin Bieber recently posted a picture of himself getting up close and personal with R&B superstar Rihanna. The picture, which captured the two posing at a New York restaurant, was posted on Bieber's Twitter account. In response, Rihanna tweeted: "Justin Bieber just flashed me his abs in the middle of a restaurant! Wow! He actually had a lil' 6-pack! Sexy."

The two have been spotted several times together.

Rihanna is in New York on a promotional tour for her new album Loud. This afternoon saw her taping an appearance on the Late Show with David Letterman, at the Ed Sullivan Theater.

The Barbadian chart-topper is getting attention on top of attention for her new, extra long, extra bright red hair extensions. She spiced up a casual denim shorts and grey top outfit with a navy blue and black leather-and-wool hooded jacket. She pulled the ensemble together with tights and boots.

Loud is being released today. The album has a noticeably lighter overtone than her previous album, Rated R. Describing the new release, she said: "I'm forever changing, growing, so it'll never be the same thing."

"This album for me was really my way of expressing myself to the fans in an unapologetic way."

In response to her other form of self-expression-namely, her Twitter account-Justin jokingly reassured Rihanna that he would get back at her.