Short for Jailbait Vacation. To travel somewhere with a lower than average age of consent with the singular purpose of having sex that would normally get you arrested. A bit of consensual, guilt free fun without the jail time.
"So did you hear that 16 is legal in Arkansas?"
"Seriously? I thought you had to go to Japan for that sort of thing."
"No sir, it's all right here in America. I think it's about time we took a Jaybay Vaycay and fucked some high school girls."
"Sugoi"
vay·cay (vey-kay)
--noun
1. A period of time devoted to pleasure, rest, or relaxation, especially one following termination from employment or school.
2. Early or temporary retirement.
3. A period of suspension of work, study, or other activity, usually used for rest, recreation, travel, or just goofing off.
4. Freedom or release from duty, business, activity, or obligations.
"Oh, you say you had to work overtime at work today? Well, today on vaycay, I woke up at noon, grabbed some sun, squashed a few brits on Xbox Live, and then closed down the bars."