According to TMZ, the ex-staff member also alleges 35-year-old Ayda - who has daughter Teddy, two, and son Charlton, six months, with Robbie - walked around in "various stages of undress"
The 'Angels' hitmaker's former assistant Gilles De Bonfilhs - who was fired in January after a short stint - has made a number of allegations against actress Ayda Field, including that she questioned him about his sex life.
According to TMZ, the ex-staff member also alleges 35-year-old Ayda - who has daughter Teddy, two, and son Charlton, six months, with Robbie - walked around in "various stages of undress" and asked him to answer questions and comment on her figure, and talked about her own intimate life with her husband.
Though Robbie, 41, is named a defendant in the documents, his former employee has not made any sexual harassment allegations against him.
The couple have yet to comment on the claims.
Meanwhile, the couple are currently embroiled in a planning row with Led Zeppelin guitarist Jimmy Page over their plans to revamp their London home.
The 71-year-old musician has lodged a third objection over the pair's bid to modernise the property, which include lowering the floors and creating bigger rooms.
Robbie and Ayda have previously altered plans after their famous neighbour complained, but after they submitted another application, Jimmy has claimed vibrations from any work could have a detrimental effect on the "extremely delicate" fixtures and fittings in his home.
He has also objected to their plans to make alterations to their garage, arguing the changes would be "extremely unfortunate in architectural terms".