Do relationships work? Like is there a point to them anymore

It all starts with "I met this guy." I'm 19 and I live in Texas (I know)We met in a threesome and continued it between the two of us due to chemistry. It's fun; fast-forward a couple months and we're still hooking up. He wasn't over his last one and I have problems with relationships so it all worked out until I ended up becoming more involved with him.He tells me that it feels like something, even though it's nothing-- and to be honest I'm starting to feel something to. It's not love -- fuck that. But i'd rather spend my time with him than alone. However, he hasn't texted me in a week and I'm considering moving on onto something else. Is this something worth cementing or going after or should I let it run its course as fling.