Why would a guy friend show interest then suddenly go cold?

Anonymous
He ended up not responding to a text where I invited him to something and its been a day. I wonder at what point he lost interest. We talked on the phone a couple days ago for hours and he kept complimenting me and mentioning how he wants a girl to enter his life, offering to give me food over the phone. He was always attending stuff I invited him to. I asked on a date once, he went and said he enjoyed it. He invited me to his sport game once. I flirt back and compliment him in return. Now he's closed off. I was the last to initiate the last call and texts. He's a friend who I got to talking to these recent months. He's ignoring now. The last text he said "see you next time." He didn't offer a definite day to see me. He usually says a concrete day like "see you Friday" or "I'll be there." For context, he's 20, and I'm 27.
Why would a guy friend show interest then suddenly go cold?
4 Opinion