IMHO

Basically Blondie had some character development off camera because he literally wanted blue hair guy to gain weight so he'll stay by his side forever and in the dream which is probably the future, blue hair is fat and old and Blondie is old with him and they are still together. Everyone be saying that the two of them should have had character development, while blue should be more emphasized because of his trauma linking to his past with Blondie, I'm just happy that it shows in the future they are happy together despite being what they hated before (Blondie hates being ugly, blue hates being fat)