During a new episode of the pop star's me & dad radio on Apple Music, the "Bad Guy" singer's mum, Maggie, revealed she and her husband were very concerned about their daughter's crazy love for Justin.
Billie's mother recalled driving her girl to a dance studio and playing Bieber's "As Long As You Love Me" as her daughter sobbed.
"It was either Marina and the Diamonds or this, sobbing," she explained. "Not just this; it was all of Justin Bieber... Any Justin Bieber song, but I just happen to remember this one really well, and the video, and Billie talking to me about it, and being excited that it was coming out and just crying and crying."
"Everyone knows the whole Billie-Justin Bieber thing, but this song was a big part of it."
Eilish added, "I would watch the music video for this song and just sob," prompting Maggie to reveal, "We did consider taking you to therapy because you were in so much pain over Justin Bieber."