How do you know if he only wants to hook up? Just seem harder to find a good catch now a days?

i enjoy going out to see bands and i usually know the band members but just becuase I go see them it doesnt mean I wanna hook up. anyways I went to go see a band that has been around for a while and are actually old friends and one of the memebers was interested in me and we have been texing eachother but he is already in a relationship. same thing happen before of another quy in another band. I am single and looking for love not just a hook up so should I make that clear when some of these guys are trying to hook up or just see what happens?