An American idiom (possibly British as well, but I wouldn't know), indicating innuendo, often though not necesarily sexual in an unsubtle fashion. It is often used to make such innuendo obvious in a situation where its obviousness will not cause problems due to people being upset by it, ex. men at Hooters: "I'd like to sample that, wink wink, nudge nudge."
It is also occasionally used to indicate sarcasm, ex. "I really enjoyed my tax audit, wink wink, nudge nudge." This usage highlights its use to make hidden meaning obvious, and therefore it is used occasionally with irony to highlight obvious meaning, ex. "She and I had sex last night, wink wink, nudge nudge."
It is notable that this phrase is featured, and perhaps originated, in a Monty Python sketch in an ironic fashion, namely that the person making innuendoes is clueless. While I personally feel that one has to see the sketch in question to truly appreciate it, the script for it (two men in a pub) has been noded elsewhere. This sketch allows the use of "Know what I mean?" and "Say no more!" to hold the same meaning, but amusingly, wink wink, nudge nudge never actually appears in the sketch! Because of this sketch, the phrase has an Austin Powers feel to it in my eyes, due to its use to wrap around blatant, overdone innuendo.
Actually, "wink wink, nudge nudge" is the form in which I've heard the expression used. Your personal experience may vary
. Reading the sketch script
, the form nudge nudge, wink wink
does not appear either.