Rich Homie Quan -- Getting High with His Baby? (VIDEO)

Rich Homie Quan just guaranteed he will NOT be getting a father of the year award, but he might be getting a visit from child protective services -- after lighting up with his 1-year-old on his lap.

Quan wasn't even trying to hide it -- he was smoking what looks like a joint while chilling with little Royal Lamar ... ON SNAPCHAT!

The rapper says something to the camera -- after blowing out a huge puff of smoke -- but it's hard to make out. We suspect he might be kinda high.

It's possible he's not smoking marijuana, and it's really a hand-rolled cigarette. But it's not like that would be any better for the toddler.