In fact, love is a game. At first, because of the novelty, both parties spent energy just to win the other's pleasure. However, when the two gradually became familiar with the game, the initial enthusiasm was gone. Love is something you can just play around with and don't take seriously, because only one person can win at the end of the game, and the losing party is often the first to take it seriously.
"How about I play a game with you."
"If I don't play, I will lose everything I play."
"Well... You don't have to worry about this, because the loser will definitely be me."