Being abstinent from mind altering chemicals for a short time period or even a long time period does not equal "living happily ever after"... especially for those of us who are in committed relationships with the the newly "sober" person.
Those new in sobriety expect everyone around them to be ecstatic and bubbling with joy at their abstinence and fully expect everyone to immediately twist themselves into pretzels to make them happy campers when they begin their endless selfish demands.
While the chemicals are gone their brains are still a mess with trying to repair damaged nueral pathways while at the same time sending impulses to the person to drink or drug... further complicating the physical and brain function issues we still have the selfish addict personality and behaviors that either are being ignored or being addressed by serious recovery efforts with AA, addiction professionals or other reputable programs.
If there is no serious work being done in recovery then my advice is to keep your distance and maintain no contact... the odds of success are so small that they are barely measurable.
On the other hand, miracles do happen but they are RARE...the addict MUST want sobriety and restoration like a drowning man wants oxygen into his starving lungs and must be willing to whatever it takes to maintain that sobriety and GROWTH as a person of character.
I am living the miracle with a wonderful man who is a RA but the turning point came AFTER I completely turned it over to God and went NO CONTACT. He ended up in jail and that was the "whatever it takes moment" for him. He works on himself constantly... he is involved with AA (Big Book meetings only) and counsels with his pastor and with his Dr. of psychology and continues to grow as an unselfish and loving mate, dad and is a man to be proud of.
That being said... it could all unravel in bad decision on his part... one weak unguarded moment and he could relapse. That is the reality of addiction and when in a relationship with someone in that position you have to decide if you are willing to enter back into a lifetime commitment with someone who does have this issue for life.