The act of engaging in male masturbation. The pringle can represents the subjects penis, while the shaking represents the motions made by the males hand to simulate a vagina and/or anus. During the shaking process, it is expected for the male to have some type of masturbation "material" such as a pornographic DVD or perhaps a pornographic magazine. The shaking process can last anywhere from a minute to over an hour, all depending on the situation.
Babe, I was shaking the pringle can all last night, but here's the sweet part, I didn't even use any masturbation material, I used thoughts brought from my spank bank.
The use of the word "blue" to refer to sexually explicit content was first recorded in Scotland in 1824. "Blue" meant "lewd" because prostitutes dressed in blue gowns.