Feels like even if Sei has feelings for Aya, shes mentally blocking out that possibility because she feels that she doesn't deserve any semblance of happiness. She acknowledges shes pathetic for not being able to move on from Yoru, and this subsequently lead her down a rabbit hole of unfortunate events shes not entirely proud of--dating men, having friends with benefits, etc. She might like Aya, but her own self-pity overwhelms any possibility of considering that fact.
I'm rooting for them, and I hope the talk with Yoru sets her straight (or... gay?)
