@PrdMomto1 thanks! I did just update above that he ended the relationship for good last week and is doing well at this point. I’m glad I stayed out of it as much as possible even though it was tough at times. All part of our kids growing up and maturing 
Yes! These experiences will help him make better future relationships knowing what not to look for in a partner.
Great job @thedreamydaisy — letting your S be in charge and making the decisions that work for him and sticking with them.
This is so important that he knows you have his back and that he can maturely make tough decisions and live with the fallout. Excellent!
Good for him! I remember when my youngest finally ended his relationship after a long drawn out period, he said he was not ready to date …he was tired of all the drama. Just wanted to hang with his buddies.
I have to admit that after the 2nd breakup, I went to his college to visit. He told me she was pushing to getting back together again and he was wondering if he should. She was SO not good for him in many ways (and vice versa), and then I told him how I felt. Just not me, but his Dad, his grandmother, etc. she was never going to change. I’m not sure if he liked hearing it or not, don’t know if he felt he’d have no support,(which is very important to him), or what. But he didn’t get back with her. I was doing quite the tap dance that morning.
Anyway, I’m happy for you all and thanks for checking back in. I really like it when we hear the rest of what happened.
We’re still learning our way since our oldest has never dated and the younger two haven’t much, either. The one thing we did right was not to badmouth middle son’s GF when they broke up. They ended up getting back together and are doing well. I’m so glad I bit my tongue and didn’t lash out at her. Whew.
Agree with @MaineLonghorn. Lots of couples wind up back together. One cannot unhear negative comments.
I think generally it’s safest never to say anything negative about a child’s ex. There must have been something that was good and attractive about that person and the relationship for it to have flourished however long it did.
I would support my kid in making decisions that are ones that s/he can live with going forward. I’m sure it’s always tough when the relationship doesn’t seem good and healthy for the individuals in it but one can support the individual and have them reflect upon it without badmouthing anyone.
Totally agree on the negative comments part and we have been very careful on that front. While S20 was relaying some of the mean comments coming his way after the break up, I just reminded him that she was hurt and upset and speaking from that place. He told me that he asked her to re-read some of her texts she had sent, and then think about how she would feel if he had sent the same messages to her. That worked well and I’m really so proud of him - think we’ll keep him 
He sounds very mature!
“No one ever said being a parent was easy!” - So true.
One of the funniest quotes I ever heard - “Parenting a teen can sometimes feel like trying to nail jello to a tree”. Luckily Op’s situation sound like it worked fine, without any jello-hammering attempts needed