A wink. It's the mirror image of ;).
I love you (;
Not a wink face. More of a lazy eye face.
If people use (; as a wink face, you should disown them immediately.
The correct wink face is ;)
Person 1: "Have a good time? (;"
Person 2: "...wtf is that?"
Person 1: "It's a wink face (;"
Person 2: "No it's not. Gtfo, retard"