Short answer
A spouse is not required to participate in an act that Islamic law prohibits. The couple should discuss the matter calmly and respectfully.
Islamic Guidance
What Islam teaches
Marriage does not make a prohibited act permissible. Both spouses should observe the limits set by Allah while treating each other with kindness.
Practical Guidance
What you can consider
Clearly explain the concern without humiliation or insults. If disagreement continues, consult a trustworthy Islamic scholar or qualified marital counsellor.
Sources
Qur'an 4:19; Qur'an 2:222-223.