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.
Another good purpose for an opposite-sidewalks stroll would be if your walking-companion owes you some money that he presently has no way of paying back, and so you and he are collecting discarded returnable containers along the local roadways to earn a little additional cash towards the amount that he owes you. Extra points if your buddy willingly carries all the bags as they get filled with returnables, so that you yourself don't have to expend so much effort on his behalf; a six-cubic-foot-capacity plastic-tubbed wheelbarrow is a handy accessory here, to help ease this "weighty" burden.