Go ahead, laugh. It's not as easy as you think because it's easily confused as a blink which is entirely different. Blinking provides moisture to the eyes. A dwink will also provide moisture to the eyes but it also conveys meaning.
Did you know that an independent study* found a single dwink is approximately 1.9 times more effective than two successive winks in conveying its message? It also showed that it had a success rate higher than double blinking by 3.14159%
According to this Wikipedia entry:
(All emphasis mine.)
A wink is an informal mode of communication usually signaling, depending on context, sexual attraction or shared hidden knowledge or intent... .
Two winks in a row often was used by the sender as a subtle way to imply something said by the sender, immediately beforehand, was "sneaky", "tricky", "misleading", or "untrue" to the receiver... .
To close and open, or "wink", both eyes is usually an involuntary action known as a "blink". Though if done intentionally, in a particular way (such as once slowly or a few times in a row quickly), while giving a sweet or suggestive look with the eyes, often with the head tilted or at an angle in combination with the shoulders, is know as to "bat an eyelash", "bat/batting eyelashes", or "flutter/fluttering eyelashes". This is most commonly done by girls, as a way of flirting, showing interest, or in an attempt to persuade the receiver (usually a gullible male) to get what they want.
I did not just make that up. That's what it says. You guys are so easy.....
A dwink, by contrast, is not intended to wile or guile anyone of any gender. It conveys a deeper meaning between sender and receiver, one of love or deep sympathy or appreciation.
Caution: Do not dwink and dwive.
*Testing was animal free.