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 jacket and a relaxed shirt (no tie needed) will ensure you're among the best-dressed dudes at every reception this wedding season. Now's the time to embrace linen—a cotton-linen blend makes for the ideal fabric for breathability and sophisticated swagger. Here's what we're pulling on before heading onto the dance floor.