opposite-sidewalks stroll

Refers to where you and an acquaintance go for a jaunt along a street or nature-trail, but you each walk "separately" on either side of the lane instead of just traipsing along side-by-side in the usual way. This less-common practice could be for any of a variety of reasons, such as that the area's sidewalks are simply too narrow for two people to safely walk double-file, or that you and your companion are cleaning up trash along both sides of the road, or perhaps you're helping each other to look for one or more scattered items that got accidentally dropped sometime earlier.