One way of telling if a guy is interested in you through a text is:
1. You could ask him, but down side is he will just think I can get a quick piece and move on.
3. Me being a dude, is you can act like you're interested and then avoid him, meaning you have better things to do then to get back to him right away. If he is interested this will drive him up a wall. I mean don't wait days before you get back with him. Also you have to mildly flirt with him...