Getty

"Vanderpump Villa" star Marciano Brunette is suing "Secret Lives of Mormon Lives" star Demi Engemann for defamation ... he says her sexual assault allegations against him are a bunch of baloney.

In new legal docs, obtained by TMZ, Marciano claims Demi is damaging his reputation by falsely calling him a "sexual predator" and accusing him of sexual assault.

He says she's lying about their interaction last year at the "Vanderpump Villa" in Italy ... claiming the kiss they shared off camera was totally consensual, despite how Demi has been portraying things on social media and TV. Getty

In the docs, Marciano says Demi's story about what went down between them in August 2024 during filming in Italy has shifted over time and he says she's "reframed the obviously consensual i

See Full Page