Why is he doing this? What should I do now? Long one, but definitely 10 points to best!?

Seems to me like this guy number three is interested in you. The debates and ing heads and coldness is just his way of dealing with his feelings for you. When s msn likes you there usualy the first to knock you down and always scrammbling to be the first to pick you back up...now with a queation i could help more so i will wait for you to ask. I really think i can help with this one.