Danielle Staub's Ex I Didn't Secretly List Our House ... She Knew All Along!!!

Danielle Staub's estranged husband Marty Caffrey is calling BS on her claims she was blindsided when he put their mansion up for sale ... because he says he told her their home was hitting the market weeks in advance.

We got Marty out Friday in New York, and he's pouring water all over Danielle's claims she found out from a friend when he listed their NJ home for over $2 million.

As Marty puts it, there's no sense in secretly listing their home when they're still living there, because there's no way he could hide that fact forever.

Marty and Danielle are in the middle of a messy divorce -- only months after tying the knot back in May -- and it's interesting to hear Marty explain why their relationship started falling apart when Danielle began filming Season 9 of "Real Housewives of New Jersey."