How can you tell if a flirt (touchy with all girls)likes you?

If the flirt is giving more attention to you than other chicks when around others.. Also if he is making an attempt to reach out to you.

Everyone flirts in a different way so there is no exact way to know for sure if he likes you or not unless you flat out ask him. If youre not comfortable with doing that then just flirt with him A LOT and ask him to hangout a lot and just get super close to him, then when the time comes one of you will/should bring up the conversation of liking each other. Good luck! :)