A person can’t really be present and emotionally available in a current relationship if still not over an ex or if the person hadn’t set proper boundaries with an ex.

I’m not a jealous person who feels threatened by exes so it would have to be very obvious to me that my partner has unhealthy boundaries with their ex and in that case I’d leave the relationship.

I agree with what rmb has said... It seems that there's unresolved issues

Perhaps he could suggest some therapy to resolve the commitment that this girl has with her ex

I have seen ex's become good friends.... Is it possible that this is going on now?

If you think that it's more then friendship then I would address it face on and I would have boundaries as well.... It's important I think that she understands she's hurting her current boyfriend by doing this and this ought to be important to her.... If it's not then I would say that's a big problem......big hug.....xo

Have either of these people asked you for your advice? If not, then sit back. A person has to want to change and be open to advice. We may think they need to change but they might not think they need to change. So if neither person has asked you for advice, and watching this dance is hurting you, I'd give you advice to back off. Don't get so wrapped up in their problems. Don't hang around them both. If one complains to you about the other, ask them to not do this. If either one wants advice, I'd tell the one who is putting their whole heart into it 24/7 to stop doing this. The one who is reserved and hung up on the ex is telling the new partner they are not #1. Nothing the over giver does will make the under giver change. But if the over giver will stop doing this and see reality for reality, they can move forward to a healthier relationship. We can't wish someone will love us more. Life is not like that.

If he's coming to you as his friend asking you for advice for him specifically, that's one thing. So be the caring friend you are and help guide him through it if he's really struggling. But I would try to not insert yourself beyond that or giving them advice as a couple. I'm trying to picture if my one of my husband's friends decided to give me advice on my relationship with my husband,,, I'd shut that down immediately.

Thank you guys so much

It's perfectly natural for us to be heartbroken over the loss of a relationship with someone we love, regardless of the reason. It's also perfectly natural to be drawn into relationships with others whether we're already in an existing relationship or not. Therefore it's also perfectly natural to be drawn into new relationships while at the same time being heartbroken over others we've lost.

The question is whether or not all this heartbreak was really necessary in the first place. If the loss was due to the death of a partner, that is totally different than if it was over infidelity or other factors that are much easier to find solutions for.