Most Helpful Guy
If you don't also pursue the man, he will lose interest.
Relationship are two way streets and the more effort you put into them, the greater the results.
If you always leave it to the man to initiate and pursue and never genuinely pursue them back, of course they will move on! You show a lack of interest in them. If you're not their first ever date, they will know that signs of disinterest are when they need to move on and use their time elsewhere.
You even say you don't give them much of your attention until you know their intentions. That gets extremely frustrating for guys who want their attention to you be validated by your attention back.
Most Helpful Girl
Easy, you are having sex too soon with them from what it sounds. They may say they want more than a hook-up, but more than likely thats BS. Since we don't know what you do while out on the dates with them, really hard to give you better answers.