He wants to keep seeing me...but he doesn't want a serious relationship?

Oh man. The guy I've been seeing for 3 months told me he doesn't want a serious relationship. Not that he wants to stop seeing me altogether---no, he talked about how much he likes being with me and how amazing the time we spent together was, and we've already made plans for doing something in a few weeks---but he doesn't like the boyfriend/girlfriend labels and all that implies. He has never been in a committed relationship but he acknowledged that I'm pretty much all he wants in a girl. So he wants to be casual. I agreed as I'm not really in a Serious Relationship place in my life right now. We made plans to meet up later in January.

But later I texted him saying that maybe I was wrong, because the idea of dating multiple people at once made me uncomfortable. This had not come up in the course of our conversation---it just occurred to me afterward. I do want to see him and at least try this casual stuff. Did I ruin everything? What do I do? I am of two minds:

1) See how being casual works

2) Kick him in the nuts for being confusing