Richie flaunted her thin frame in the black getup, flashing some major sideboob as she strode through the lot. The sides of her legs -- from ankle to waist -- were also exposed in Richie's see-through getup.
The mom-of-two (to daughter Harlow, 5, and Sparrow, 3) capped off her Old Hollywood glam look with an elegantly swept updo that revealed two large silver earrings.
Just last week, Richie was getting her tan on with pal -- and fellow mom -- Jessica Alba during a getaway trip to St. Barts. The A-list friends showed off their toned post-baby bikini bodies and enjoyed the sand and surf in the company of Alba's husband Cash Warren.