What should I do if the opposing attorney wants to have

Applying a tax deduction to retirement benefits is normal when parties are getting a divorce. The reason for that is that retirement benefits are tax deferred. The usual deduciton is 20%. If  you are both keeping your own retirement benefits, it is normal and proper to do the 20% tax discount.  If the retirement benefits are going to be divided equally by qualified domestic relations orders (QDROs), you  don't need the 20% discount as you will both simply pay the taxes on the money when  it is drawn out or received at retirement. There is nothing sinister or inappropriate with your spouse's attorney advocaitng the 20% deduction.