I like to think this conversation between Lina and Amelia happened sometime within her first week as a part of Lina and Gourry's posse.
I always thought it was strange that Amelia never showed any romantic interest in Gourry. Not only is he good looking; but a chivalrous, "knight in shining armor" type seems right up her alley. Then I remembered that Martina gave up on Gourry because he's a dumbass (and she felt that a princess needs a smart husband). So that's why this comic happened.
[cross-posted to theslayers]