What is the one thing (okay you can pick two) but the one thing that your significant other or fuck buddy or a stranger, in some of you guys case , do that just pushes the envelope so to speak and makes you horny as hell where you can't even think straight. Not necessarily a move in bed but prior too. A look, something that is said, how they are dressed etc.
In seriousness? When she makes sincere eye contact. Wearing an eyepatch, I've found that most either stare at it, or won't look me in the eye at all. Understandable, but when she makes direct eye contact, she's showing that she's looking at ME, and not my outer appearance...same as when a guy looks at YOU, and not just yer tits. You can say a lot with just your eyes, if you want to.