Charli xcx had Paris seeing right through her latest fashion statement ... literally ... because she wore a top that did little to shield her nipples.

This brat turned heads Tuesday night during Paris Fashion Week ... she stepped out of La Pérouse following Saint Laurent's Men's Spring/Summer 2027 show and after-party ... rocking a daring sheer black top that left nothing to the imagination.

Charli paired the eye-popping look with a tiny black skirt, pointed heels, and a quilted clutch as she navigated the crowd outside the exclusive Fashion Week gathering.

Check out the pics ... if Saint Laurent owned the runway, Charli may have stolen the sidewalk.

The singer appeared completely unfazed by the attention ... confidently strutting through the Paris night while photographers snapped away from every angle.

Of course, fashion risks are nothing new for Charli, who's built a reputation for embracing boundary-pushing looks throughout her illustrious career. Whether she's onstage, at a premiere, or heading home from a party, subtle has never really been her thing.

And judging by these photos, Charli's latest style philosophy is pretty simple ... free the nipple!!!