Sign
Signs are actions a person does/says to subtly indicate to another that they are interested in them, be it romantically or sexually. Life is really just a question of reading the signs.
Example:
Dude #1: Man, that girl just told me she wants someone to watch Frozen with
Dude #2: It's a sign!
Dude #1: Man, that girl just told me she wants someone to watch Frozen with
Dude #2: It's a sign!