Triangles are stable when all three legs are connected.
What that means in a three-way relationship is that each day is securely connected.
Secrecy If the separated man is concerned that a new relationship might inflame the other partner’s decision, he may choose to keep that new relationship quiet.
Those drifts can come from so many causes: illness, financial strain, too many obligations without reward, personal insecurities, stages in life that produce self-doubt, boredom, neglect, too much hostility without reparation, or just plain growing apart.
Relationships that are new have not had the time for enough negatives to accrue that can outweigh the reasons to stay together.
If the separated man isn’t sure about reconnecting with his partner and a new relationship would make that option far less likely, he may not want to lose those choices so chooses to keep his options open by separating those two worlds.
The heartache that arises if and when those clandestine relationships are discovered never harbors a good outcome.