Amber Rose -- I'm Dating French Montana ...'s Brother

Amber Rose has a connection to another soul with a broken heart ... we found out she's dating French Montana's brother Zack.

There are reports that Amber and French are together, but in reality ... French and his bro hang together all the time ... thus the confusion. That's why we got a pic of Amber, French and Zack at Knott's Berry Farm about a week ago.

Amber keeps her distance when they're in public, but we know she's seeing Zack. They were out at a strip club and a nightclub in NYC over the weekend.

As for why the secrecy ... we're hearing Amber doesn't want to make things more difficult with Wiz Khalifa, given their nasty split and a looming custody fight.