Paris Hilton has put her foot in her mouth by double-crossing a firm she cut a deal with to hawk stilettos bearing her name – and then bragging about it on social media, a new lawsuit claims.

New York-based Antebi Footwear Group — designer of the Paris Hilton Footwear collection of stilettos, flats, wedges and other footwear — slapped the heir head with a $2 million breach-of-contract suit Saturday in Manhattan federal court.

The counterclaim demands Hilton refund $2 million in royalties Antebi has paid the hotel heiress since it began selling her footwear products in 2007 and other money damages.

It alleges that Hilton back-stabbed Antebi by tapping a rival footwear company, Retouch, last year to license a competing footwear line, “Parisian Parc” in violation of a contract agreement with Antebi.

Hilton then took to Twitter and Instagram to promote the new footwear line, the counterclaim says.

“Obsessed with all my new shoe designs. Love how all the fabrics & colors go perfectly with my bags,” she tweeted Sept. 16, according to the suit.

The counterclaim is in response to Hilton socking Antebi with a $1 million-plus lawsuit last month alleging she was unlawfully squeezed out of royalties after the firm allegedly failed to honor its licensing agreement.

Antebi claims Hilton broke her agreement first. The new filing also seeks Hilton’s suit be dismissed.

“[Paris Hilton Entertainment] breached its covenant of good faith and fair dealing to Antebi by means of its aforesaid intentional and malicious acts and by destroying and injuring Antebi’s rights to receive the fruits of its relationship with PHE and those rights granted pursuant to the exclusive licensing agreements,” the counterclaim alleges.

Hilton’s April suit claims she is owed more than $1 million in royalties — based on 8 percent royalties of net sales — under a licensing agreement with Antebi. She is also seeking a court order to terminate the licensing agreement, which runs through the end of this year.