So there is this guy that we were both flirting back and forth, slept together like a month ago. haven't seen eachother for a few and then crossed paths and saw eachother briefly. He texted me and said how nice it was to see me, then today nothing. So I texted him a sad face and he replied back, I felt kinda sassy, so I texted him back "mmmk" and he put "yeah, mmmk". And that was it. I was like wow someone is sassy, and he didn't respond. What could be the problem?