The party split up, Priestess become field medic with Lizard Priest, Dwarf teach Negima magic trick, GS goes gob hunt with Elf.

Then after that GS return to farm, he sounds gritty & immediately ask CG for stew, CG know something wrong and ask if all the gob quest (it's spring, the goblins population explode) and he become trainer make him exhausted, GS disagree. CG finally understand and say she also feels sad because the remain of old farm is turned into training ground & all the memorial of their childhood including with GS' onee-chan is gone, that's not it either.

She finally give up and ask what's going. Then GS basically rant how he feel lonely and he can't stop thinking about that girl (Priestess), he don't know what to do, and he can't figure out what the goblins is planning. All of that in front of CG. The last line is "The chirping of canary doesn't give enough solace"

And they aren't even separated for that long, less than two days actually.

Without the build up it won't feel the same, but if you insist.