Sources tell us Amber is dating Def Jam Records' Vice President of A&R Alexander 'AE' Edwards, who we're told she's been seeing for a few weeks now ... but she's known him since Tyga and Blac Chyna were together few years back.

We're told Tyga and BC both approve of their respective friends banging -- but don't hold your breath for a double date. It'd take more than this for Chyna and Tyga to reunite.

Remember, Chyna and Amber have been super tight since Chyna and Tyga split a few years ago. We're told the ladies had a little spat this weekend -- unrelated to Amber's new bf -- but they've already squashed it.

While Chyna and Tyga won't be dating ... we're told it's very possible their paths will cross more often now, due to Amber and AE.