All liabilities resulting from such joint income tax returns hereafter filed, including the fees for tax accountants and preparers, shall be borne by the parties in the same proportion as their respective incomes (less their respective deductions) bear to the taxable income reported on such returns, except that, in no event, shall the party reporting the lesser net income in any calendar or fiscal year be obligated to pay, or contribute, on account of any taxes or tax liability, any amount in excess of the amount that he or she would have been required to pay had he or she filed a tax return separately for the tax year in question.