Most Helpful Guy
I hate to break it to you but this is a red flag that comes up with many guys. Do you talk and hang out in person? If you want to know if he's interested, that's probably the best thing to do, but to me it sounds like you two don't talk much in person.
But from what you've told me - it sounds like he isn't interested. I can't point fingers but maybe he's found someone else? Give him a call and ask him straight up.