“Congratulations.” Thanks to a new SKIMS campaign (yes, that SKIMS — Kim Kardashian’s brand), you can now watch Post Malone frolic through the wilderness wearing nothing but cheeky boxers and briefs.

Growing up in Los Angeles’s San Fernando Valley—where it’s always at least 10 degrees hotter than the rest of the already-sweltering city—I quickly learned to prioritize comfort and ease in my ...