If you cannot decipher his intentions for you, then here are the true signs you need to look for to tell if you are just an option:
1. Out-of-the-blue appearances
Though he may have the decency to ask you over a text message about what your plans are tonight, regardless of how fast you respond, he takes forever. So you are left wondering what is actually happening or if you may wind up spending the evening with him. Instead of just carrying on the day as you would normally, you try to forgo meals (just in case of dinner) and check your phone every 5 minutes.
Then, like a bolt from the blue, there he is, either offering the chance to do something fun or messaging a short apology like, “sorry, never mind.” This shows pure unreliability. If he cared, he would respond within a reasonable time or at least give a reason for why he had contacted you in first place. Last minute requests may be pleasant at first, but treat them with caution.