When Celine realizes she could have feelings for her best friend Jenna, she is utterly mortified about confessing, knowing it will ruin their friendship.
"Promise to n-never f-forget me" Marinette said through tears, Adrien pulled her into a bear hug, "only if you don't" he said, stifling the tears. Marinette hugged him back. Little did they know, they broke their promise.