As a divorce lawyer I often have to advise clients that the conduct of their spouses during the marriage will not effect the financial outcome as determined by a court.
That is not always the case, but successful conduct cases are few and far between, with the court usually determined to eschew any attempt to award or deduct "points" from either party in their roles as husband and wife, as being divisive and irrelevant to the division of assets.
The recent Court of Appeal case of Rothschild v De Sousa is an interesting illustration of where the court might take post separation conduct into account where that conduct has been the manner in which once of the parties has conducted the matrimonial litigation with the effect of significantly depleting the available resources due to huge legal fees.