I wear these, and they have to be - without a doubt - the most comfortable flip flops I've ever worn. Super light and comfy, and they stick like glue on rock slab for the outdoors. Best part is I didn't even have to buy them, I won them in a bouldering competition.
https://www.evolvesports.com/BUCK.htm
My boss wears a hawaii shirt and sandles, so I want to try braving wearing these to work.