The D.C. “retro-forward” socialite group Dandies and Quaintrelles hosted a bike-oriented Seersucker Social over the weekend — a summer-themed followup to the popular Tweed Ride in the fall. DCist photog maxedaperture has the participants in all their tandem bicycle–riding, finger sandwich–eating, croquet–playing, refreshment—swilling glory. (The lede photo comes courtesy of jim_darling.) Waivers in hand, seersucker-clad riders assembled at Meridian Hill Park to ride through Rock Creek Park to Hillwood Estate, Museum and Gardens in Northeast…