Will my pension (which SS considers a "windfall" against my own SS benefit) be deducted from the amount that I can draw from my ex-husband's monthly benefit?

Hi,

That depends on whether or not the pension you receive is based on your work for a government agency where you didn't pay Social Security taxes. If it is, then you'll probably be subject to the Government Pension Offset (GPO) provision. In that event, any divorced spousal benefits for which you would otherwise be eligible would be offset by 2/3rds of the amount of your government pension (https://www.ssa.gov/pubs/EN-05-10007.pdf).

Best, Jerry