My crush suddenly stopped replying my texts?

Okay, there's a boy I had a crush since the 6th grade I'm in 8th now. He knows I like him. I don't have any classes with him this year so I got his phone number through one of my friends. I started to text him and he replied back quickly and we were having a nice convo and everything, we we're talking about skateboarding and then he asked me if I wanted to hang out which made me very happy but he had a gf at the time, he's single now. Last week I asked how's his weekend and he replied "good hbu" then I said "pretty good though but I wish I could do something fun like hang out with you or something." And he didn't reply so I thought you know maybe he's busy. But then I texted him again a different day and he didn't reply. I feel like he's ignoring me or something. I keep trying to text him but he doesn't reply. What's happening? I need help.