Making their debut post-engagement appearance, Kim Kardashian and Kris Humphries were arm-in-arm at the Meridien Beach Plaza in Monte Carlo, Monaco on Friday (May 27).

The 30-year-old E! reality star showed off her multi-million dollar sparkler as she and her New Jersey Nets basketball playing fiance checked out the sights at the annual Amber Fashion Show.

Tweeting about the overseas excursion, Kim excitedly tweeted, "Backstage at the Matthew Williamson fashion show! He is amaze! Prince Albert & Charlene here too! About 2 go on stage! I always get nervous"

And while Kim and Kris have confirmed their plans to wed this summer, Miss Kardashian's brother Robert isn't 100% sure that the walk down the aisle will take place.

Talking with The Hollywood 5, Rob said, “I just don’t feel confident because Kim has always been so… like, she’s how old? She’s just been through a lot of relationships, she just always gets hurt or [doesn't] find the right dude, but, you know, Kris is actually a really good dude.”

Also chatting about the moment he learned of his sister's nuptial plans, the 24-year-old told, “We were having, like, a family dinner, and we didn’t know what it was for, we just thought everyone was in town. [Kim] has a ring on, [but] we didn’t know what it was for, and we didn’t believe her, and we thought it was a joke… then it just got crazy… it was really bizarre.”