Next time just ask the guy instead of surreptitiously photographing his bum?
It's probably some mall-brand that starts with B and wishes it was Diesel. I'd guess Buffalo, but they have a Buffalo logo patch. If it's the pocket stitching design you like (as opposed to what looks like a Balmain-wannabe pocket zipper detail), have a search for Diesels on eBay.
For your reference, Balmain pocket zippers:
classic (mid-2000s) Diesel pockets: