1 If it always seems your co-worker is staring at you when you see her, that’s a sign. 2  You can usually tell when someone likes you if you catch her staring at you all the time. 3  Use it as an opportunity if you want to go out with her. 4  Your co-worker is flirting with you if her finds any reason to touch you. If she didn’t like you, she probably wouldn’t do this since it is a little obnoxious. 2  Smiling is one of the signs a co-worker is flirting with you. 3  If you notice a co-worker always smiles at you at work when there is no good reason for it, she may like you. 4  You can find out by asking her out if you like her.