It appears that Halsey has a little issue with Demi Lovato and her song "Cool For The Summer"
In an interview with "Paper" magazine Halsey says she's frustrated with “stars who exploit bisexuality for their music,” and she specifically points out "Cool For The Summer"
"The closest thing to queer representation you get in pop are songs sung by straight women, and they’re more about experimental hookups,” adding “Bisexuality as a taboo: ‘Don’t tell your mom’, or ‘We shouldn’t do this’, or ‘This feels so wrong but it’s so right.'”
And if you didn't already know, Halsey is openly Bi-Sexual.
Demi isn't staying quiet about what Halsey has to say though. She jumped on her Twitter and responded with this -