'RHONY' Carole Radziwill Defends Herself From Sai De Silva's Epstein Questions

Carole Radziwill defends herself from costar Sai De Silva's incessant Jeffrey Epstein questions in the new season of "The Real Housewives of New York" ... demanding to know if Sai really thinks she'd take part in the pedo's heinous crimes.

The trailer for 'RHONY' Season 16 dropped Tuesday ... and it captures a moment where Carole is accosted by someone on the street who mentions her appearance in the infamous Epstein Files.

Carole has admitted to having a friendship with Epstein and his longtime associate, Ghislaine Maxwell, over the years ... though she denies she knew anything about his wrongdoing at the time.

Sai then appears in the next scene ... asking Carole if she ever went to Little Saint James -- Epstein's private island in the Caribbean.

Carol says she didn't ... then fires back -- in an offended tone -- "You think I'm part of an international sex trafficking ring?"

We knew there was tension between the two ladies while filming ... sources told us this moment happened -- and they actually beefed throughout the entire season because of this moment. Sai even seemingly referenced it in a cryptic Instagram post shortly after filming wrapped.

Despite the tension -- or perhaps because of it -- sources tell us producers are thrilled with Carole, who appears in every episode of the season even though she's only a "friend of" the cast. We're told she was offered full-time cast member status but politely declined.