Sylvester Stallone is firing back at his estranged wife, Jennifer Flavin, by denying that he’s hiding any of their marital property … but wholly agreeing the marriage is dunzo.

The actor filed a response to Flavin’s divorce petition in Palm Beach County, FL — which clearly states Sly has NOT engaged in the intentional dissipation, depletion and/or waste of marital assets … this, according to docs, obtained by TMZ.

It doesn’t get more specific beyond that — neither did Flavin, BTW — but his attorneys make crystal clear that SS is not doing anything that could be labeled as moving/hiding assets.

Sly also has an answer for Jen’s request for exclusive use of their Palm Beach mansion — and to that, he says … hell no. He’s officially opposing her ask, letting a judge know he’s firmly against that.

One thing Sly concedes … there’s no remedy to fix this mess. He acknowledges their union is “irretrievably broken” — he’s also cool with her restoring her maiden name.

As we reported … we’d heard from sources directly connected to the Stallones that the straw that broke the camel’s back might’ve stemmed from an argument over a dog that Sly wanted, but which Jen didn’t.

Sly, however, denied that … telling TMZ the Rottweiler, Dwight, didn’t trigger anything … and he and Jen had simply grown apart. He added, “I have the highest respect for Jennifer. I will always love her. She’s an amazing woman. She’s the nicest human being I’ve ever met.” He’d previously told us he loved his family and wanted to deal with this privately.