He sounds like he wants what he can’t have, so since he knows you’re interested now, he’s acting uninterested. However, he might just be scared that something real could happen, or he’s a flaky guy. You just got ask him to hang out and go from there. If he doesn’t even respond to two of you just hanging out, he’s not the one for you. If he does say yes, tell him you like him and want to go on a date with him. If that’s too straightforward, when you’re hanging out bring up a place you’ve always wanted to go to. Mention you have no one to go with, but that it’d be a nice place to go for a date. See how he responds from there. Hope it all works out! :) If he acts like he’s not into you anymore, you deserve so much better, someone who will proudly show he likes you!
You just have to go for it and tell him you like him. Even if he doesn’t have the same feelings, if he’s a good friend he won’t ignore you. He might want to give the both of you some space after so you don’t feel awkward, but not ignore you. Ask him to hang out and when you see him, you just got say it. Say that you like him more than a friend now and want to go on a date with him. Don’t be scared, no matter the outcome, everything will work out, if not with him, you’ll find someone else! :)
The only way you’ll really know is if you ask him, no harm in asking him out this time for the second date. But, even if you were the one to ask him out the first time, still give him a call and ask if he wants to hang out again. Hopefully he’s just being shy or got busy, but if he sounds not interested when you ask to see him again, it’s his loss! Don’t be afraid to go for what you want, you won’t know till you ask!