I'd say it depends on how it's done. Here, that actually serves the story as we follow the squid sisters and that's what lead us to the two frolicking around. It's better done than just a couple bystander that are there for one panel joke and making comments on it.
Eromame does it as a running joke and in a somewhat cute way as it can be a story within a story, so it's fine, but frankly, I prefer this author way of doing it as it blends more in the whole thing.