I can only speak for MA, but the courts absolutely go after a second wife's assets and income when calculating an alimony award after modification. Technically, the second wife's income/assets are only supposed to be included if a purposeful transfer of assets has been proven to avoid alimony.
All of us have been to court and know what really happens, my husband and my self have a prenup - are not in business together - do not file taxes together - have separate bank accounts, but the MA courts used my income added to my husband's income to calculate the payment to my husband's former wife - her income increased by $14,000 after our marriage. Reasoning of the court - my husband now had more excess income to pay alimony - he supports her, I support him.
This almost split us up - but then I got mad - and I have made it my mission to change the law in MA; but my advice, don't get married, commit to each other, but protect the person you love from this same type of court abuse - what does a marriage license mean anyway except a license for an ex-spouse to go after more income.