We caught up with the actress on the streets of NYC Monday, where she weighed in on the Diddy-Cassie saga ... which had a major update last week. As we reported ... hotel security footage from 2016 surfaced on CNN Friday, showing the rap mogul beating on his ex.

Diddy has since apologized for the incident, calling it one of the darkest times of his life ... but JF isn't showing him so much grace -- instead slamming the whole thing as "disgusting."

Check out our clip -- Julia sounded off on the footage, noting ... "My heart goes out to Cassie." It's a brief slam, but it's impactful -- and you can tell she means what she says here. She also sounded somewhat choked up while speaking her piece.

Julia -- who's a feminist icon in her own right -- has been very vocal about women's rights in the past ... revealing recently that she's avoided being intimate with men almost entirely the last couple years.

Specifically, in the comments of a TikTok video slamming a Bumble ad that shamed celibacy, JF confessed she's refrained from sex for 2.5 years -- and she touches on that here.

Julia tells our photog ... "Just focus on yourself. Prioritize yourself. And you'll see that once you decenter men that everything you want in life will come true."

While Julia may be celibate, she isn't single ... reportedly telling Variety in April her boyfriend -- whom she didn't name -- lives with her and her son, Valentino. No sex, though, it seems.