Naughty Nessa!

In case anyone had doubts about the status of Vanessa Hudgens' relationship with Austin Butler, this giant hickey on her neck should answer their questions!

On Tuesday afternoon the brunette starlet went to her yoga class in the valley, and later in the day she tweeted, "Happy birthday to my best friend @ashleytisdale. The crazy one who always makes me laugh. Love u always baby girl." Wonder if the ladies got to party for Ash's 28th b-day? And who would have guessed that Ash is the crazy one? We thought for sure Vanessa was the wildest High School Musical hottie in the group...