When you invited him to the New years fireworks, he couldn't believe it. He was so excited! He told his friends about how he would spoil you but then Tanjiro brought up how that could be overbearing; Genya also mentioned how girls had used Zenitsu for money in the past, which led him to get into debt. He panicked, and you paid for everything instead without him realizing, "They're about to start.. I hope they aren't too loud." He said softly, walking with you to the picnic spot you paid for.