Hmm… Well body language isn't too reliable. Reason is that most of the times your body speaks without you even knowing it. - Meaning your body might make gestures that are so ingrained into your nature that you might not even realize that you are doing that particular gesture. And it takes years of practice to learn to decipher body language. The safe rule of thumb is, "If you think it can't be what it looks like, you’re probably right!" Like today, this girl sat right next to me in the bus. She sat on a folding seat beside me. When she got up to leave, she bent down to fold the seat. The seat wasn't budging, so she bent a little too much, so much so that her hair fell off her forehead and she was really close to me. Her breath was falling on my thighs. Now an inexperienced person would have jumped to the conclusion, "Oh wow! She probably digs me. That’s why she got so close to me.” And then the inexperienced person might try to make a move on her, only to discover she couldn't care less about him!
So how did I figure out she wasn't trying to give me a green signal to muster the courage to talk to her and maybe ask her out? Well, I looked closely at her eyes. Even though they seemed to be focused on directly above my thighs, some more careful inspection revealed that she was really trying to concentrate on folding the stubborn seat. Her line of sight was tilted toward the seat. Had it wavered toward my thighs, that would have been worrying. But that could be dismissed too as accidental. She could have gone one step further and tried to look directly into my eyes, as I was watching her head directly in front of my face. She didn't do that either. And if she had really wanted to give me the heebie-jeebies, she would have looked into my eyes and smiled. Now when a girl does THAT, it means you BETTER talk to her, because that's body language for "Hey, I think I like you. Why don't you stop being a scaredy cat and try chatting me up? I will make it worth your while ". And normally this ends in friendship at the very least or serious relationship in cases where the girl is just too dazzled by the guy’s personality.
So you see, I have just given you a lecture on how to read a girl's body language and be very sure if she likes you or not. You may notice that the more intentional the body gesture, the more probable that it is what you think it is. You just have to learn which gesture is deliberate and which one isn't.