Best time for the "what are we" talk

I've just started hanging out with a guy, we have been sleeping together, I'm pretty sure he's interested in more than sex, he already met the parents (long story), he asks me about family, job, life, and when he talks to about us, he does talk about the future, so, I'm pretty sure there's more to this than sex. 
Is there a set time period for when I should initiate the "what are we" talk? 
Thanks!