Next time he jokes about "wanting to take you off the dating market", just say something like:
When you're ready to do more than want it, let me know and we'll talk terms.
I don't really wanna have a 'relationsihp' talk yet. I'm still deciding about him, and while the jury's still out on my end, I don't want to accidently offer a commitment I'm not ready to make. I'd rather sort of hint that he's gonna have to 'up the ante' about how often I'd like to be in touch with him/how much attention he's gonna need to pour in m y direction, so things can heat up and heat up and maybe get to that point of exclusivity (in, like, a month or something, perhaps? I'm thinking after 2-3 more good/solid/quality chunks of time together.....?) I am going to play it by ear. I want to hint that I need attention, so he might get the clue that if he doesn't want things to fizzle and fritter away with me, he's gonna have to keep the heat on, but I'm not ready to suggest more. Then maybe by the end of August I'll be so sure about giving an exclusive thing with him a try that I'll be ready to throw down the gauntlet and suggest it or ask him if he's thought about it or whatever.... I'll see. When I'm ready to commit to it if he asks, then I'll broach it.