I think that financial issues can be one of the reasons that MLCers delay divorcing or not, but it is not the only one. If it is MLC their brains are like Swiss cheese and they are driven by their emotions and fears, as well as their pocket books.
In some cases they delay divorcing because they do not actually want to marry the OW, and there is pressure coming from her. In others they are genuinely undecided what they want . . . . MLC is not unidimensional with the MLCer being driven by cool financial considerations, though I agree it can be part of it.
