Paris Hilton's Sex Tape Partner Being Stalked?

Rick filed a request for protection last week in L.A. County Superior Court, claiming 44-year-old Heidi Thomas -- his former real estate agent -- showed up at his home several times on September 16 ... refusing to leave the property.

According to Rick, Heidi threatened and terrified his daughters, leaving her "soiled pants" on the front door step ... which may have been a contributing factor in her arrest.

Rick claims Heidi is emotionally unstable and appears homeless -- and wants a judge to keep her at least 100 yards away from him and his family at all times.