Ron was madly in love with you, although you didn't feel the same way about him. You were talking to Harry, and Harry said:

"Rina, I heard you wanted to get on the train..."

Harry didn't finish speaking, and Ron interrupted him.

"Chaca, chaca, chaca, chaca, chu, chu!"

Ron said, looking at you with a smile while sitting down in his seat and spreading his legs, looking at your cleavage. You made a disgusted face when you realized what he meant...