I think maybe when he intensely feels an emotion he lets out a smell that matches it probably Bakugou’s.x.Waifu
The smell he let's out is perceived differently by different guys as the smell they like, so if I were a dude and I liked citrus scents then I'd get a citrus scent from him... we wont know what the grey flowers mean unless the story progresses
What happened to the flowers? It grey did the smell go away or something? Am confused and pissed at the same time(╯°Д °)╯╧╧