It is difficult but not impossible to terminate parental rights. It is not something you are likely be about to do yourself. If you would like a consultation on your specific issues, email me at firstname.lastname@example.org.
So there is no misunderstanding, my answer to your question does not establish an attorney/client relationship with me or my firm and such a relationship will not be established unless and until you personally retain me or my firm to represent you.
I think that your course of action might better be served by having the non-offending parent file for sole legal and physical custody of the minor child. If granted, it would not terminate the rights forevermore, but it would strip the parent of rights to the child until such a time as that parent could establish to the court that there has been a change in circumstances.
I would seek the advice of an attorney in your area.