Can't stop kissing… Birthday girl Paris Hilton is all over boyfriend Cy Waits during talk show promotional blitz

 Paris Hilton made sure to celebrate turning 30 with a kiss from her boyfriend Cy Waits, but the couple couldn’t keep their hands off each other for the rest of the day.

The heiress was lip locked with Waits outside David Letterman’s New York studio, where she had been filming The Late Show.

Despite it being her birthday, the famous blonde wasn’t about to stop working on her business empire and was promoting her new iPhone app during a promotional blitz in New York.