I didn't think it had anything to do with sex, I've only heard PinkieParrot's definition. It's sort of hip hop slang thing to insert "izzle" into words--for "rizzle", would mean "for real", "reality televizzle", would mean "reality TV". It goes back a long time. Like the song "Double Dutch Bus" from the late 70s or early 80s, with whole "Dizubble Dizutch" part.
In elementary school, my friends and I would have "Secret Languages", really a similar type of language game to the "izzle" business, and not unlike Pig Latin, that also inserted "THG" or "ARB" into words, so we could speak to each other without others understanding. I'm 28, and my best friend and I still use it! It comes in handy!!