It looks like Harry wrote a song that Ariana may be recording for her next album. That doesn't mean he wrote it for her or that...well, you saw this coming...Harry and Ariana are dating.
It just means Harry wrote yet another song (with another writer, called "A Little Bit Of My Heart") and she bought the song rights--check out the proof at ASCAP. End of story. Not nearly as romantic or as exciting as some would like you to believe.
Harry is collaborating with OneRepublic's Ryan Tedder, however, which just adds more fuel to the rumor that Harry wants to split with One Direction and go solo.
According to The Sun (via EntertainmentWise), an insider squealed, "The new relationship with Ryan will come in handy if Harry ever try his hand at going solo. Harry and Ryan have been working on new material together. They've met a number of times before with the band but have never worked together properly."
The source added, "There's a mutual appreciation there. If there's one person to get the best out of Harry, it's Ryan."