David Tutera -- host of "My Fair Wedding" -- is a hardcore sex addict ... and his penchant for hookers destroyed his relationship with his husband ... this according to legal docs obtained by TMZ.
We broke the story ... David (pictured above left) filed documents to end his 10 year domestic partnership with his longtime partner Ryan Jurica. The couple is expecting a surrogate to give birth to twins for them in July.
Now, TMZ has learned ... TWO DAYS before David filed his docs in L.A., Jurica filed legal docs of his own in Connecticut hoping to end the civil union -- and the papers contain some explosive allegations.
In the docs, Jurica blames David's uncontrollable sexual appetite for the destruction of their relationship -- claiming, "After repeated attempts at marriage counseling and therapy, we have been unable to save our relationship due to [David's] addiction to sex."
Jurica continues in the docs, "[David] has engaged in a pattern of hiring sex escorts and prostitutes to support his addiction."
Jurica says David refuses to seek help for his hooker addiction.
There's more ... in the docs, Jurica also demands full custody of their unborn kids. David also filed a request for full custody in the legal docs filed in L.A..
Jurica also says David makes all the money in their relationship -- more than $1 mil per year -- and he needs money to survive (house payment, car payment, etc).
In the docs, filed by Jurica's lawyer Bettina D. Hindin, Jurica also says ... David was the one who broke up with him ... and he took it so hard, he went into a downward spiral and checked himself into an in-patient alcohol rehabilitation center.
TMZ did some digging and learned Jurica has been arrested twice in the past 5 months -- once for DWI and once for public intoxication.
8:30 PM PT -- David just released a statement to TMZ, calling the allegations baseless and untrue. He tells us, "I am saddened by these developments; I am angered by the lies; and I am committed to moving beyond this painful moment to focus on my professional commitments and the upcoming birth of my children."