I have a solution. But to me this is what I observe from some of my guy friends. But you have to ask other ppl to observe cos you can't see it yourself.

When a guy is interested in you, as he walks side by side next to you, he tends to tilt and learn towards you... get it?

| | <--- lets say this is you


the situation will be like this:
| | \ \

urm... kay i dun think u understand.. oh well at least i tried.