She wasn't in a relationship with Hayasaka to begin with though, so I don't think it makes it NTR. Even though she may have feelings for him, she kinda just let something happen to her like that to forget temporarily and she evidently does feel guilty about it, so I suppose she NTR'd herself and her own feelings of Hayasaka but it's not strictly NTR.
I didn't think I'd explain the nuances of NTR online, but anyways, thank you very much for the translation!