While Luna was mostly focused on pleasuring the cock in her mouth, she still was attentive enough to hear Hermione's words and blush. She had always found the older girl quite attractive herself, though she never imagined Hermione would return the feelings.
Luna continued her work on the member eagerly. She had always been a very open minded and curious girl, it was natural for that to spill over into the bedroom. Sex really was something that Luna found vastly interesting and she always loved exploring it.
Hearing Hermione's warnings, Luna did not let up, wanting to taste Hermione as she came. As she heard Hermione begin to orgasm, it wasn't long after she felt the first bit of come on her tongue, but she didn't shy away and kept her head moving on the cock.