He suddenly gets turned off?

I've been seeing this guy for about a month now, and we haven't had sex or anything, but to get us used to each other we sext quite a bit. It's been going great but recently he's suddenly getting turned off, I'm super confused! One moment he's asking what I'm doing (if ya know what I mean 😉) then the next he's not interested! I've asked him if there's anything wrong but he hasn't said anything out of the ordinary other than, "I just don't feel like it anymore."