Forget Wife Swapping - Try On-call Swapping
Many many many years ago I worked in the City with a bunch of souls who, as was the norm at that time scattered to the four winds after a few months; We all kept in touch and used to meet for Friday beers in Convent Garden or some such.
All of us were on call for our respective masters and would get calls throughout our evening of highbrowed discussion on the finer things in life.
Long story short, we'd swap calls, and dispense advice to bemused sounding Ops departments all over the City and beyond. No one actually died, but I do think some of the on-call logs made for interesting reading / explanation come Monday morning and one person struck up a long and meaningful relationship with an Ops person.