Floppy relationship triangles are essentially unstable and the outcomes are not only unpredictable, but often dire.
There are many factors that can affect these triangulated relationships and how they are combined can affect the outcome in different ways.
In either case, a relationship they begin while being separated is just another kind of infidelity.
Men who do not find themselves ever satisfied with only one woman are clearly not likely candidates to change that behavior in the future.
Over time, and especially if they’ve been in disappointing other relationships, they miss each other again and valiantly try to “make it work.” If they don’t see those patterns and correct them, that process will occur until they either wear each other out or find someone they’d rather invest in.