Rapper YBN Cordae is livin' the dream right now -- he's got a tennis superstar girlfriend, he made XXL's prestigious "Freshman Class" list, and he just dropped a debut album that's getting great reviews.
Yeah ... that's probably why the dude was so chipper when we saw him out in NYC!!!
As we previously reported ... the 21-year-old and Naomi Osaka -- #2-ranked tennis player in the world -- were getting close back in April and spending a lot of time together.
The young couple is officially official now (our source is pretty rock solid) .