The fifth annual World Naked Bike Ride went off without a hitch around the country yesterday, from San Francisco to Grand Ferry Park in Williamsburg. But while the naughty bits were on full display in SF, New Yorkers kept things a bit more demure (after all, anyone can go topless, but no one can be pantsless in public). That doesn't mean there weren't a lot of, er, fully-formed and finely-aged butts on proud display. Click through to see some semi-NSFW photos from the event, as well as a video below—just remember, you've been warned.