My suggestion would be "total abstinence" or else. Because without it, the alcoholic will not be able to manage the relationship and manage to stay sober and recover. If you're going to help them do this -- I hope the below information will help you to be able to help them.
Unfortunately, to prepare yourself to help them -- it will take more work for you than it takes them.
Healthy Love is the result of "Choice." Unhealthy Love is the result of an "Emotional Dependency."
If we are going to recover, from alcohol addiction or love addition -- we must learn to use our Intellect to make our choices and decisions, instead of trying to live making Emotional choices and decisions.
I'll try to keep this as brief as I can. But, it wont be easy.
The First Step is to "Identify the Problem." We need some information about the problem so that we can identify the problem.
First, I want to direct your attention to thinking in the same terms like we do with drinking and the alcoholic... to set up a reference point and starting point for understanding.
a. Normal drinkers drink alcohol by choice. They choose what to drink, when to drink, how much to drink, and they stop drinking at any time they choose.
b. Alcoholics do not drink by choice. They drink because they are addicted to alcohol. They cannot safely take a drink at all -- because taking the drink triggers a physical and psychological change in their body and mind -- that prevents them from controlling their drinking "by choice." Once they drink, drinking is mandatory. This is why we say that they are Powerless over alcohol.
Now, think of what I wrote above about drinking, alcoholic, and alcohol, and change the words "drink" or "alcohol" or "alcoholic -- and use, instead, the words "love" or "relationship" or "addicted to love."
We know: the only solution for the alcoholic is, "total abstinence". So, our first working objective to deal w/ the love/relationship problem must become: "total abstinence". In other words "plugging the jug on this relationship."
After the person has "recovered" from their "love addiction" we'll help them learn a "healthy way to love."
Here are some references to read, that will hopefully give you a better understanding of what I'm trying to convey here:
Read: Biochemistry of Love, Relationships and Recovery
Read: Emotional Sobriety
Addicted to Love or Relationship = Has formed a dependency on the biochemical results produced in the brain, that creates the euphoric sensations in the mind and body.
Think of this in terms of the "how and why" that the alcoholic becomes addicted to the substance alcohol. I believe the best way to get a layman's understanding that we can work with is to:
1. Read the Doctor's Opinion, in the Big Book. Each time you come to a word that is "alcohol" or relates to "alcohol" -- change this word to "love" or "relationship." Then,
2. Read Chapter 3, "More About Alcoholism" -- and with this reading, turn it into Chapter 3, "More about Love" or "More about Relationship."
3. Bill Wilson, wrote on pg 143, Big Book:
"To get over drinking will require a transformation of thought and attitude. We all had to place recovery above everything, for without recovery we would have lost both home and business."
Now, take what Bill wrote -- and change this from "drinking" to "love" or "relationship".
Example: "To get over "this relationship" will require a transformation of thought and attitude. We all had to place recovery above everything, for without recovery we would have lost both home and business."
4. Read: "Spiritual Experience" in Appendix II, in the back of the book Alcoholics Anonymous. Here, do the same that you did with the other readings: Change the words from "drinking" to "love" or "relationship."
This background information will provide you with enough information so that you can view "Love and Relationships" from a different angle of understanding and perspective which will give you more options to choose to solve the problem.
Now, you take the person through "taking the 12 Steps" on this specific problem = "Using the 12 Steps on this Problem in our Life"
Here's what the objective is:
1. To get the individual to commit to "plugging the jug" on this relationship. Then,
2. To "produce a transformation of thought and attitude" that will help this person get over this problem.
We'll call this Phase One in their development. To move on to Phase Two, we've got to get past Phase One first -- and then, teach them some skills in regards to picking and choosing healthy relationships.
I hope that helps,