Austin Butler Clarifies Why He Called Ex Vanessa Hudgens A 'Friend'

Austin Butler has learned a major lesson ... never refer to your ex of nearly 10 years as a 'friend' cause you will catch a lot of flak for it -- just like he did this week. The actor had to clarify what he meant from an interview he did almost a year ago ... when he pulled a Biz Markie and referred to Vanessa Hudgens as just a pal. At the time, he was recounting a story about how the idea of playing Elvis first…