Sonja Morgan may have once had a “RHONY” tagline about going commando, but this undergarment brand has her stamp of approval.

The reality star shared a series of beachy snaps on Instagram last week, striking several poses in Spanx’s bright red SpanxSculpt Halter One-Piece.

There’s more to her plunging V-neck swimsuit than meets the eye, however, as it combines the brand’s shapewear-like smoothing and compression technology with UPF 50+ sun protection and chlorine resistance.

“This style is very flattering and quality is on point,” one satisfied shopper wrote, while another called it “super comfortable.”

“Don’t miss the Marilyn Monroe feeling at the pool!” a third reviewer quipped of the plunging one-piece, praising the adjustable halter straps.

Though Morgan wrote that Spanx’s signature bold red hue has her rethinking her favorite color, her suit also comes in black and tan.

She paired it with the fuchsia version of Spanx’s Beach Button-Down, plus matching heels and statement earrings, for her day in Sag Harbor.

The linen layer is designed to dry quickly and comes in seven shades, including several crisp, luxe-looking neutrals.

Given Morgan’s currently filming for “The Golden Life” — a new E! series featuring several past “RHONY” icons — perhaps we’ll be seeing her suit again on-screen come fall.

Why Trust Page Six Style Shopping

This article was written by Hannah Southwick, Commerce Associate Editor for Page Six. Hannah spies deals on actually affordable celebrity-worn styles, puts celebrities’ brands to the test and finds the beauty products that keep stars red carpet-ready. She consults stylists and industry pros — including celebs themselves — for firsthand product recommendations, trend predictions and more. In addition to writing for Page Six since 2020, her work has been featured in USA Today and Parade.