Are we in a relationship?

Sara • 23
Okay, so I've been dating the same guy since like mid May. Dude had been in different relationships since like 8th grade or something, and I haven't been in any. I'm 23, and it just didn't happen. I've dated around though. Anyways, I'm like 95% positive he isn't seeing anyone else, and he's the only guy I'm seeing right now. How do I ask him if we're in a committed relationship or not? Like I just can't figure out when or how to bring it up. Any advice would be greatly appreciated!