Selena Gomez is teased a new song that has her talking about her teenage years. Fans can't help but think it's about Justin Bieber — and we can see why. Gomez teased a snippet of a new track on her Instagram story that has her singing, "I had a dream, we were back to 17, summer nights... never growing up." As Elle points out, Gomez just so happened to meet Bieber when she was 17. Gomez probably isn't going to ever say whether or not this is about her ex. Mainly because she no longer wants to talk about him . It's something she made very clear in 2015. "I would try to promote something that I loved," she told Marie Claire, "and the entire interview would be about my personal life." That's why we have to look at what we know about this new song: Gomez is one of its writers. According to ASCAP, Gomez recently registered a new song called "It Ain't Me," which she co-wrote with DJ Kygo, which means it very well could be about her own life. Gomez posted a black and white photo of herself to Instagram without a caption, but click on the photo and you'll notice she tagged the Norwegian producer DJ. This may also be a hint that she's in the studio putting the finishing touches on this track. Is that a smirk we detect? Like, she's about to drop a musical bombshell on us?