In my opinion both of you like to be spend time together. The age of your relationship is seems not too mature, so don't be too close with him.
He said to you that he is just your friend. But always keep in mind that friendship is the first step toward strong relationship.
You are only 17 and you will find lots of such guys in your life ahead. May be in future you may find a much loyal and attractive guys.
So, don't involved with him and be a good judge.
Your judgement power will certainly let you to select a good partner.