To the refuser I would say:
Lay your cards on the table, be honest and tell your spouse that you don't like and/ or want sex with them.
Allow them to seek sex elsewhere. If you can't provide your spouse with a basic biological need and you will deny the spouse seeking it elsewhere then you are a selfish pig and you have no right holding your spouse hostage.
Yes this might blow up the marriage and the family unit but your marriage is already a lie and dishonest because you are avoidant and not honest.
To the refused I would say:
Lay your cards on the table, be honest and advocate for yourself.
Your spouse is being selfish and it's time for you to be selfish for yourself.
Let them know that celibacy is no longer an option and they can either start fucking You enthusiastically in a meaningful intimate manner, which may mean seeing a therapist, counselor or sex therapist OR you will either be fucking someone else or seek a divorce.
An avoidant non answer will result in the refused's choice.