Obvious

How girls flirt:

1. She calls your name softly.
   
2. She laughs when you say something funny.
3. She flips her hair while talking to you.
4. She touches your arm when she talks.
5. She comes so close to you, sometimes.
6. She plays with your hair or tries to put make up on you.
7. You catch her staring at you.
8. She imitates your laugh, your way of talking that makes you like her even more.
9. When you go to movies or hang out with friends, she is almost always next to you.
10. She asks you who you like or would go out with, seemingly interested.
11. She criticizes you on a girl you like, and talks about how she likes someone just like you.
    
12. She says, "No, I`m not telling you who I like!" with a big smile on her face.
13. Her friends inside and outside of school know, and say she talks a lot about you.
14. She tries to talk and spend time with you as mush as possible.

How guys flirt:

1. He looks at you a lot, and sometimes straight into your eyes.
2. He calls you to talk about nothing at all.
   
3. You hang up on him. He calls you back.
4. He tries to make you laugh even if he gets hurt in the process.
5. He imitates your laugh, which makes you laugh even louder....
6. You are invited so many times to a group hang-out.
7. He uses every possible ways to touch you, your hair, arm,...etc.
8. He likes teasing you among a group of friends, but when it is personal, he is serious.
9. He tries to make a chance to be next to you.
10. His voice gets softer whenever the two of you talk.
11. He uses the first thing that pops into his head to start a conversation with you.
12. He pays attention to what you talk, what you do, and your surrounding.
13. He remembers things about you, even little things you mention in casual conversation.
14. He admires you (smart, considerate....) and tries to tell you how he feels indirectly.

P.S. Thanks a lot, werticide, for providing food for thought !!