"I've been friends with Laura for the past ten years – before she was my nanny – and I completely stand by her," Moakler tells PEOPLE exclusively.
A source adds that Boyce appeared in at least one episode of Meet the Barkers, the MTV show about the unconventional family life of Moakler, a former Playboy centerfold, and her now ex-husband Travis Barker.
Boyce, 37, who worked for the Lowes for seven months in 2007, claims that Rob's wife Sheryl created an "extremely sexually offensive and hostile work environment...behaving in a... perverted, disgusting and crude manner."
At a press conference Thursday, Boyce's attorney Gloria Allred argued that Rob Lowe, as an employer, was equally liable for any alleged sexual harassment that occurred on the job.
(In her lawsuit, Boyce does not accuse Lowe of any direct sexual harassment.)
Larry Stein, the Lowes' attorney, said Boyce's lawsuit "seeks to drag (Lowe's) wife and children into the fray" with "false allegations."
Sheryl Lowe also spoke out against Boyce in a statement Thursday, calling Boyce's allegations "sickening."
Lowe, 44, and Sheryl, 46, preemptively filed lawsuits against Boyce and two other ex-employees on April 7. They claim they're the victims of an attempted $1.5 million blackmail scheme, led by their former nanny, Jessica Gibson, 24.
A deposition of the actor and his wife is set for May 19 and 20, respectively, in Santa Barbara, Calif., where they live.