Boyfriend worries...

I've been getting pretty serious with this guy I've been seeing but last night he tells me that he doesn't want to put a label on us, ie, boyfriend and girlfriend. He says that whenever that happens he becomes super protective and somewhat jealous. He doesn't want to be that guy anymore and I see that in the way that he acts with me compared to how he tells me he was in previous relationships. I just want to help him get over that. Do y'all have any advice?