On the subway, I saw a young couple.

The boy leaned close to the girl's ear, I didn't catch what he said, but the girl’s face suddenly turned red, and she raised her hand to hit his shoulder.
The boy dodged, grinning mischievously.
I sat across, pretending to look at my phone, but my ears were perked up.
The girl lowered her voice and scolded him: "Are you thinking about this stuff all day long?"
The boy blinked innocently: "I didn't say anything, maybe you're just imagining things."
The girl got even angrier and hit him again.
At this moment, the subway arrived, and the doors opened.
An elderly woman wobbled in, just standing in front of them.
The boy immediately stood up and said very naturally, "Grandma, sit here."
The old lady repeatedly thanked him, sat down, looked up at them, and smiled warmly: "Young man, you're really good, and your girlfriend is pretty too."
The boy scratched his head, smiling honestly: "Grandma, she's not my girlfriend yet, I'm still chasing her."
The girl snorted nearby, but the corners of her mouth couldn’t help but turn up.
The old lady looked at the boy, then at the girl, and suddenly lowered her voice, speaking in a seasoned tone: "Young man, chasing a girl isn’t just about giving up your seat. You need to let her know that besides her, there’s nothing else in your mind but her."
The boy was stunned, and his face turned bright red.
The girl was also stunned, then burst out laughing.
I sat across, almost holding back my laughter.
After the old lady finished speaking, she winked at me.