The Game -- Meet Up With Justin Bieber's Ex-Chick ... Is All About The Biz

The Game puts work before pleasure ... 'cause even though the rapper is hanging with one of Justin Bieber's former hookups -- it ain't funny business, just money biz.

Sources close to model Chantel Jeffries say The Game definitely wants her ass ... as the star of his upcoming music video shoot. We're told that's what they were discussing while they grabbed a bite at The Ivy Tuesday afternoon.

Besides, they're both kinda spoken for -- Game with his ex-fiancée, Tiffney Cambridge ... and Jeffries with The Weeknd.

Still, we know Game's hip to the paparazzi game -- so he damn well knew lunch at The Ivy would start a buzz ... about him and Chantel, and his video.

It's called showbiz for a reason.