Under special circumstances, yes.

He loved one girl and then they broke up and he is now in love with new girl. Now this first girl returns and their is lot of ruckus. new relationship is not that strong an old one is not that weak.

This can happen only when connections re really deep from all sides and no greater reason exists for break up like cheating. Love is strange but this happens some times.

This primarily happens with high empathy people, those who have hard time figuring between the nuances of love and sympathy.

If you had any such experience, do share. This happened to me quite a few times when there was transition time between relationships.