Should I tell him ....?

Definitely hang out with dude sober, and talk to him about what he said. Just lead into telling him, but make sure He's not just drunken babbling, and not actually ready for the next level. I'd say there's a pretty good chance considering you've been FWB for so long that he just doesn't know how to approach you about it. Or back off if its getting awkward, but still be friends until he's ready.