There was no lesbian erasure, she clearly just wanted to keep him by her side as her childhood friend since that spot wouldn't change regardless of whether she started daring or not, plus the guy gave up right away after seeing how she smiles differently to him than to her partner at the end.
Reading this in one go hit me like a truck, if you're the kind that really focus in the story and doesnt judge it by how it looks or how rational it would be in the real world you're gonna love every part of it or at least most, definitely gonna re-read this in the future and the novel too