Have Relationship Questions? Ask a Counselor for Answers ASAP
You are mentioning that you spent weekends together. It is of importance to clarify what had happened during the week (is one of you involved, is it a distance relationship, etc)
As to how to approach this- since men tend to be more logical and not so emotionally in tune, perhaps you could ask him to share what may be some of the things that had led him to his decision and to explain as to how he had arrived at that conclusion.
Then, after her shares his part, you will hopefully know more about his motives and if you still feel that you want to pursue with the relationship ask him if there could be anything the two of you can try to give the relationship another chance.