Sora usually picking up Isa flowers on his way home from a thing he goes to regularly. One evening he goes out with friends afterwards instead and didn't pick up flowers. The next morning the empty vase is sat on the table blocking where Sora normally eats his breakfast.
Isa moving his arms to let Sora cuddle up to him on the couch when Sora approaches but Sora just sits on the other end of the couch cause he didn't notice or thought Isa was trying to get space/move to block him. Isa thinks Sora is mad at him and buys him take-out to apologize without actually apologizing, despite not knowing what he did. (he didn't do anything. Sora thought Isa didn't want touching.) They cannot and will not communicate like normal people.