A guy who is texting you a lot but not asking you for a second date is keeping you as a dating option, but isn’t prepared to commit to that second date.
This is a guy who isn’t that interested in a second date.
The first date was decent enough and relatively enjoyable, but he didn’t get what he needed out of it.
He enjoyed parts of the first date but not others.
As a result, he realizes that there are some things about you that he likes, but at the same time, he didn’t feel that much chemistry with you.
If he texted you telling you about how much fun he had and asks you about your availability to go on another date, he is interested in you.
This shows that he is keen on taking the next step.
He is not just commenting, he is actually trying to take decisive action to see you again.
Texting you after the first date and asking you to further elaborate about something you were talking about on the date is how he is keeping the conversation going.
He is showing you that he was paying attention to the conversation that was had and he wants to continue it.