While I believe you didn't intend to lead him on, that you have a genuine interest and just weren't ready (and perhaps still aren't, given that you told us " I just want him to be interested and have that one night stand MAYBE".
You were enjoying being flirted with and feeling wanted and thinking about the ONS.
He was enjoying being flirted with and feeling wanted and thinking about sex.
Then when you turned him down, it seems to him that you didn't -actually- want him. Consequently all your flirting was partly fake. That you didn't want him, you were just enjoying the attention.
So you want the attention again, but he's not interested in playing that game, because he no longer believes your attention was real.
The flirting game with him is over.
If you want to have sex with him, text him and say you want to get him on his own, when and where?
He's still interested in sex and he'd still enjoy genuine flirting, but he won't just flirt because he doesn't believe it now.