Really confused.

A couple days ago a guy who I was really good friends with told me he liked me. Yesterday I told him I liked him back and all he said was... cool.I am trying to figure out what he means by that but... well...I don't know. Just help.

This guy is trying to act smooth and be cool. This guy doesn't want to be like, Oh really?!? You really like me?, and be estatic. He doesn't want to make it seem like he's making a big deal out of the fact, though he does like you. If he admitted he liked you, he obviously has feelings for you. He'll soften up to you as time goes on.

lol, thats funny, that be somehtin I'd say a couple years ago. Ya I'd agree with modernwinter

Yeah I think its more of a teenage 'lingo' , maybe he used that word so he wouldnt show his real emotions by saying something like 'oh im so glad', usually they dont like to show there emotions /teenage boys...but more than anything I believe he just used it because either he couldnt think of another word or thats just how he talks ...