'Jersey Shore' Angelina Pivarnick Dishes on JWoww Feud

'Jersey Shore' outcast Angelina Pivarnick's made her return and, even though it got a little nasty with the crew, she says they went out on good terms ... until JWoww started running her mouth again.

Angelina tells TMZ ... despite a heated confrontation with JWoww and Snooki on Thursday night's episode of "Jersey Shore Family Vacation," she was actually in a decent place with everyone once her reunion with the cast was done filming.

Then ... she heard JWoww was trashing her about a fan's Change.org petition, which Angelina claims is both immature and incorrect. She tells us this is what led to her "Jersey Whore" diss toward JWoww last week.

There's a soft side to this feud, though -- Ang concedes JWoww's a good person and respects her for being a good mom ... but believes they need to work out their differences in a more grown-up way.