I know . . . zombie thread . . . but WTH.
If I anticipate participating in non-cycling activities or events as part of a ride, I often wear my "stealth" cycling gear. I have a couple of relatively plain MTB jerseys with small zippered pockets or basic jerseys that look like athletic t-shirts except for the back pockets, trekking shorts with a few pockets, and MTB shoes that look just like regular athletic shoes. With my helmet off, few people would realize I'm a cyclist by my attire.
If I'm just stopping for water, snacks, etc. on a training, group ride, or organized cycling event, I have no problem wearing full kit into a store or cafe.