He was rejected by Luca. Not only that, Luca also flicked his forehead hard with his fingers just a few seconds after he voiced the suggestion.
For a few seconds, after he voiced the suggestion, Luca seemed to freeze, probably not expecting the words he said, but then the black-haired man regained his composure before punishing him by flicking his forehead hard.
Luca scolded him for being too playful, and he laughed at the younger man whose face turned red because of what he said. He didn't know if it was because of anger or embarrassment, but Finn liked seeing Luca make such an expression towards him.
Luca scolded him for being too playful, and he didn't rebuke the scolding at all, thinking that he was just joking, so he shouldn't take things seriously between him and the black-haired man.
