"Real Housewives of Potomac" star Stacey Rusch is pulling back the curtain on her emotional reunion with Wendy Osefo ... following Wendy's recent arrest on a slew of fraud charges.

Stacey appeared Sunday on "Watch What Happens Live" ... revealing she met with Wendy last week, and the emotional moment led to them holding one another.

She goes on to say she fully supports Wendy and can't wait for her to tell her story.

As we reported ... Wendy is fighting to clear her name, claiming she's the victim of an illegal arrest and wants all charges against her and her husband, Eddie, to be dropped.

Wendy is currently facing 16 counts, seven of which are felonies for allegedly making false/misleading info fraud.

As for Stacey ... we got her out in NYC this past Friday and asked her about the buzz surrounding her apparent divorce with Thiemo Rusch -- check out the clip.