how to get him in his feels?

Tabby
So there's this guy I really like and he likes me and we talk all the time, but I can never really talk to him about anything serious. We snapchat a lot and when there's nothing to say we'll just send weird selfies. I've mentioned to him before that we don't talk about anything very deep but he just kind of brushed it off and moved onto something else. How do I get him to open up??