A casual summer wedding is supposed to be fun, not stressful, right? But that doesn't mean you won't be hit with that dreaded thought: Damn, what am I gonna wear? Even if you aren't an actual invited guest—perhaps just somebody's plus-one—you'll want to look your best and feel good. Thankfully, this is the easiest kind of wedding to pull a look together for. Our fool-proof suggestion for a comfortable, breathable suit made from Italian seersucker (in an unconventional green color) and a washed shirt will ensure you're among the best-dressed dudes at every reception this wedding season. Finish things off with a textural silk tie and ground things with a chunkier slip-on shoe. Now's the time to embrace a laidback yet sophisticated swagger. Here's what we're pulling on before heading onto the dance floor.