Asking parents to pay student loan debts

SO and I have been married for 6 years. We are financially frugal, doing well with 401k, roths, investments etc. Together we make ~200K before taxes, insurance, and pre tax contributions. Our outstanding debts include mortgage, husband’s car, and his student loan debt. His student loans are approximately $115k.
I have been wanting to throw the majority of extra money at his student loans to just be done with them. Husband has been resistive wanting to save money for house repairs (nothing that’s a safety concern, regular upkeep and goal projects).
His parents are retired and live very comfortably. They frequently remind us once they are gone we will inherit (along with his sister) a good amount of money and their very nice house.
I would like him to approach his parents about paying off his loans now and subtracting that amount plus anticipated growth on that amount from his inheritance in the future. I heard it explained once that parents see themselves passing on wealth, but they are passing it on when their children are already stable and have made a life without it, so why not do it sooner when it will set them for better success going forward. Husband has been wanting to think about it.
Husband is unsure about approaching this conversation with his parents.
Do you all think this is a reasonable request?