Joanna Krupa Sues Hey, Brandi Glanville ... Keep My Vagina Out Of Your Mouth

EXCLUSIVE
0121_Brandi-Glanville_Joanna-Krupa_tmz_2Joanna Krupa plans to clean out Brandi Glanville ... finally making good on her threat to sue over months of trash talk about her baby maker.

According to legal docs ... Krupa claims she experienced severe emotional distress when Glanville went on "Watch What Happens Live" ... and told the world JK has a stinky beaver. Now Krupa's slapped her ass with a defamation suit.

Glanville reiterated the scentiment multiple times ... and Krupa went ballistic about it last month.

If Joanna wins the suit -- filed by her attorney Ray Rafool -- she'll finally force Brandi to pay up ... but the move isn't without risk. Krupa's lady parts will now be up for discussion in open court.

The witness list should be ... interesting?