“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.

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 interaction as one of sexual misconduct and then as sexual assault” to give herself a storyline.

Marciano is also suing ‘Mormon Wives’ producer Jeff Jenkins … he says production “aired the allegations in a way designed to maximize impact while cutting Marciano out and denying him any meaningful opportunity to respond.”

He says production had “obvious reasons to doubt Engemann’s account, including inconsistencies, delay, and facts known to Production that undermined the claims” … but says the show “amplified the same accusations for profit.”

In the docs, Marciano includes alleged texts from Demi he says she sent after leaving Italy. He says she stayed in contact with him from months through calls, texts, FaceTime and invited him to visit her in Utah and California.

Marciano claims Demi even shared her location with him and says, “That behavior confirms a continued relationship, not a person reacting to sexual assault.”

In the docs, he says Demi’s false claims have resulted in “lost professional opportunities, harassment by strangers, and lasting harm to Marciano’s reputation.”

Marciano is suing for defamation and going after Demi and the producer for damages … and he wants a “narrowly tailored injunction” that prohibits them from “repeating and republishing all of the statements that are adjudicated by this Court to be defamatory.”