Jeff Bezos, Lauren Sanchez Pose for Vogue, Celebrate Engagement with -

Jeff Bezos and Lauren Sanchez look damn comfortable in the country and in the city -- $160 billion will do that for ya -- as they posed for a western-themed spread in Vogue ... but also partied with their celeb pals in Bev Hills.

Their latest engagement party went down Sunday night ... a private affair at the home of Barry Diller and Diane von Furstenberg with a serious who's who guest list.

Stars Flock To Jeff Bezos & Lauren Sanchez's Engagement Party

Gallery Launch Gallery Stars Flocking To The Party Launch Gallery Backgrid

The guests of honor mingled with Kim and Khloe Kardashian, Kris Jenner and Corey Gamble, Mick Jagger, Oprah, Leonardo DiCaprio, Chris Rock, David Geffen and Robert Pattinson and Suki Waterhouse.

TMZ has learned the couple invited Jewel to perform at the event, and guests partied in a throwback disco dancing room. BTW, a few more from the mega guest list -- Jessica Alba, Salma Hayek, Rita Wilson, Scooter Braun, Barbra Streisand and James Brolin, Bob Iger and Lauren's ex, Tony Gonzalez. They're cool like that.

As for Lauren and Jeff's wedding day ... she talked to Vogue about planning the massive event, but sounds like they don't have a ton of details yet. They've only been engaged for 5 months, after all.

However, the couple was happy to strike several poses for multiple photo shoots ... one on his Western Texas ranch, and another with a glossy, futuristic theme that looks kinda spacey.

THREE TIMES THE FUN!!!

Makes sense, as Lauren says she's getting ready for her trip to space aboard Blue Origin's New Shepard capsule. She also talked about their $10 billion philanthropic efforts through the Bezos Earth Fund -- as she put it to Vogue, "This is the most important work I’ve ever done, ever.”

And, not that anyone had any doubts about this ... but Lauren confirms she'll be taking Jeff's name when they walk down the aisle -- "Uh, yes, 100 percent. I am looking forward to being Mrs. Bezos."