The song "Quay Lại Lại Yêu" by Ngô Kiến Huy talks about the long-distance relationship and the questions that arise when two people are apart. The lyrics express the longing and doubt of one person wondering how the other is living their life, and if they have moved on to someone else. The song encourages the couple to not give up on their love and to overcome any obstacles they may be facing in their relationship. It also emphasizes the importance of communication and not making impulsive decisions that could lead to regret. The singer expresses the pain of love and the determination to make things work out, despite the challenges. The song ultimately conveys a message of hope and reconciliation in love.