01/25/2013 11:25 pm ET Updated Jan 28, 2013

Liberty Ross Files For Divorce From Rupert Sanders Following Kristen Stewart Affair

Liberty Ross has filed for divorce from her cheating hubby Rupert Sanders ... TMZ has learned.

Ross just filed her paperwork in L.A. County Superior Court.  She's asking for joint custody of their 2 children -- ages 5 and 7. 

Ross, who is repped by disso-queen Laura Wasser, is also asking for spousal support, as well as attorney's fees.

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