ET has the details...

Former chef PETER CLEMENTS is the third ex-employee of ROB and SHERYL LOWE facing a lawsuit from the star and his wife -- and ET has the court papers right here!

In the docs, the Lowes level numerous, surprising accusations against the chef for his allegedly wild behavior, including disclosing the Lowes' private phone number and address to strangers; making false statements about the couple; and throwing parties at the Lowes' home without their knowledge or prior consent while they were out of town. But those allegations aren't even the worst of it!

The Lowes also accuse Clements of having sex with strangers on the their bed (and without their knowledge or consent) while they were out of town; stealing from the couples' medicine cabinet and distributing the prescription meds to his friends; overcharging the Lowes for food; stealing that food for personal use and for his catering business; and taking mail from the Lowes' mailbox and destroying it.

Clements is accused in the lawsuit of ten primary transgressions total, including breach of a confidentiality agreement, defamation, intentional infliction of emotional distress, and trespass.

According to the papers, Rob and Sheryl fired the chef last December upon learning of his conduct -- but at the time, they didn't press charges against him. The papers go on to state that they allowed Clements to sign a "Release and Settlement" agreement by which he would agree not to break the original confidentiality agreement. And according to the docs, the Lowes filed this lawsuit against him after learning that he allegedly continued to share their personal and business information with third parties.

Earlier today, ET reported that Lowe and his wife had filed papers against two former nannies, LAURA BOYCE and JESSICA GIBSON.