The Bible allows for self-defense.
The Bible also allows for the death penalty but most Christians are against it.
Self defense includes defense of the whole self: mind, body, and spirit.
Marriage is intended to make two bodies one, but sin is a reality. One person can and often does break that bond, and the God-intended one body of the two no longer exists.
To force one person to live as if it did, to condemn one person’s body to lifelong control, to punish one person for another person’s sin, is never God’s way.
If you support lifelong abstinence for all those abandoned by their spouses, please show me where the New Testament supports enslaving/punishing/imprisoning one person’s body for someone else’s sin.