Forget fur, we prefer Bieber in the flesh! Naked flesh, that is -- after Justin was slammed for wearing a REAL fur coat Monday night, animal-rights activists jumped on the pop star and trolled him on social media for wearing the nasty mink coat.

But JB doesn't seem to mind, it was business as usual as he hit the hiking trail for some mountain jogging on Tuesday. It's his new routine and we must say, it's paying off!