This already exists, it is called flirting. Given two socially well adjusted participants it allows either party to back down without hurting the other parties feelings and allows everyone to save face. The person escalating the flirtation doesn't feel bad because they aren't outright denied and the respondee isn't put in the awkward situation of having to deny someone. It also has the added benefit of allowing each…
Flirting has a high signal to noise ratio. There are also many issues with unintentional signalling.
That's the whole point. The noise provides plausible deniability.