should agree to mortgage my home which is paid for my husband';s bills?

My house was bought by dead first husband and me , I wanted to leave it to my children by my first husband. my new huband is not even on my deed of the house and it's still in my dead husband and my name, I want my kids to inherite my home.I don';t like my husband son and he would add him to tnherite the house also. He wants the house to have his name and mine on the title and he will make the payments on the mortgage.the amount he wants is 70,000 dollars. Help me please!