A will can be challenged as Single Old Cat said. The execution of a will is going to take a long time --- sell some of your asset(the house, in this case), payback your debts, arrange your responsiblilities (supporting your young kids to 18 years old and your spouse if he is unable to support himself). finally come to the stage of distributing whatever left --- this is your parents turn to claim the share.
The lawyer, who will do the house buying for you, knows how to do the loan paperworks. It is common that the money for house buying is not borrow from a bank, but from a individual (a relative a friend).
You and your hu*****and have equal titles on the house. You also sign the loan together. Each of you should be liable for the full amount of the loan, so that part of the loan will not disappear if one of you die. These are all very common terms, Your laywer knows.
Now you have to consider the payback terms. To best proptect your parents benefits, "The full amount should be payback within 30 days of date of your death." However, I strongly suggest that you do not treat your hu*****and so hard. You should discuss this with him, and arrange a payback term feasible for him -- say 5 years.
Do consider your hu*****and's situation in the event you die suddenly. He alone has to face funernal arrangements, daily life supports and worse, the accuations from your side of relatives and friends, either you die of illness/accident/suicide. Trust me, poeple who was heart-broken, turn their pain to anger, your hu*****and would be an easy target to blame. They are unreasonable for that peroid of time.
If it is an accident, he might be serverly injured too. He will need money cover the med bills and salary loss.
Be mercy, Give him some time to pay back your parents loan. Set an exception, that in case he is disable permanently, he does not need to payback the loan.