TCWDM : Sources are lovepunky.com and psychologytoday.com. Or search 'How to scientifically tell if a guy likes you?' ^_^
Working hypothesis :
I affect him.
Could not test his hormones.
Could not scan.
IF I affect him, the angle of his body should always be directed towards me.
IF I affect him, he would be looking my way.
IF I affect him, he would be curious about me. (But I could not make little accidents... =__=)
IF I affect him...
These are all not entirely and concretely scientific, so... ask?
Should make his heart wild again. We'll see how his adrenalin fares when I'm near.