Hello Quazaa & welcome
It sounds as if you two have a special bond, which is obvious when you are together, but, perhaps, when you are apart, your ex remembers the hurt he felt when you left him, and remembers that you have been with another man, and wonders if you will leave him again, or whether taking you back is the right thing to do.
Maybe, to ensure that it doesn't happen again and that he doesn't have to think about your other relationship, he thinks that it would be best to end the relationship.
I may be wrong, but that's how I interpret it.
If you have been getting on so well, and as you have a child together, I think that it might be worth trying to save this.
I would recommend relationship counselling.
Is that a possibility for you?
Good luck!
