When Valerie was looking at the fireworks, her eyes flashed the moment when she kissed Leo. Her heart skipped a beat and she stole a gaze at him. Here he was, sitting with arms in the arms of Ellie. What the hell was she thinking! he was nothing but a monster, but he still has a mark of her lipstick. Didn't anyone notice, she was too embarrassed to tell him.
It's not that Adam and Ellie didn't notice it, Adam wanted to see his face, when he would realise that he roamed in the fair with a lip mark. He Chuckled, just even thinking about it. Ellie indirectly tried to wipe it, but he didn't let her touch his face. And she couldn't tell him because she was jealous. In the end it just remained there.
