Guillermo Diaz who worked with Britney Spears on the "I Wanna Go" music video shares his experience:
"Britney Spears' "I Wanna Go" music video (2011)
"I was supposed to be in the beginning of the video where she says my line from Half Baked then she points to me and I give her a thumbs up," Diaz says about the initial plan for the pop princess' "I Wanna Go" video. But a few days before the shoot, someone dropped out and Diaz suddenly found himself with a bigger role, driving around with Spears and pouring milk on himself.
Diaz remembers Spears and kind and powerful, and, while she was shy in between takes, she came to life when the camera started rolling. "I'm so proud to be part of something with Britney Spears because I just love her and it was such an awesome moment in my life," he says.
He even has a sourvenir from the experience: "I remember driving home after the shoot in my milk-soaked pants because they let me keep the jeans.""
The full article where the actors talks about his others works can be found here: EW