Jessica Simpson wears underboob-baring dress to Jessica Alba’s party

Pop singer-turned-fashion mogul Jessica Simpson has turned heads with her choice of outfit for Jessica Alba’s birthday party.

Jessica Simpson’s latest look might take your breath away.

The pop singer-turned-fashion mogul, 41, was snapped leaving Jessica Alba’s birthday party at celebrity hotspot Delilah in Los Angeles on Thursday, clad in a tan-coloured cutout bandage dress by Hervé Léger, Page Six reports.

She paired the underboob-baring look – which originally retailed for $US1390 ($A1965), but is currently on sale for $US695 ($A982) at The Outset – with gold platform heels and a matching metallic clutch.

Jessica Simpson showed off her curves in a body-con dress. Picture: Hedo/Backgrid

The face of Flonase hit the town with her husband, Eric Johnson, by her side. The former football player kept it casual in denim and boots.

Simpson shares her three children with Johnson, who graduated from Yale alongside Alba’s husband, Cash Warren, in 2011.

The ‘With You’ singer wore a jaw-dropping dress while her husband kept it casual. Picture: Backgrid

The singer’s sister, Ashlee Simpson, also attended the birthday bash.

Los Angeles-based makeup artist Adam Burrell posted a photo of the sisters glowing beforehand, with Jessica sporting a deep tan and pouty lips and Ashlee, 37, rocking nude lips and a smokey eye.

Celebrity hairstylist Aaron Carlo called it a “Classic Burrell Beat”.

Jessica has been focused on her namesake clothing line lately, and recently revealed she’s “draining” her bank account to expand the company.

She’s also been open about her weight loss journey, recently celebrating her “hard work”, “determination” and “self-love” by posting a bikini selfie – featuring a suit from her billion-dollar brand, of course.

This article originally appeared on New York Post and was reproduced with permission