St. Vincent "still has feelings" for ex girlfriend Cara Delevingne.
The 34-year-old musician - real name Annie Clark - recently split from the model, and despite rumours that she's moved on with 'Twilight' star Kristen Stewart, sources say she's not quite over Cara yet.
A source said: "Annie is totally in love with Kristen but she still has feelings for Cara. It ended dramatically and neither of them really wanted to break up, but neither of them could seem to make it work with their hectic schedules."
And the unresolved feelings are taking a toll on 26-year-old Kristen too, as she's having to proceed "cautiously" with the relationship for fear of getting hurt, should Annie decide to run back into the arms of her 24-year-old former beau.
The source added to HollywoodLife.com: "It really is a love triangle in the classic sense. Annie is torn between Kristen and Cara, but her focus is on Kristen right now. Kristen is proceeding cautiously because she knows she could get hurt."
The 'Café Society' actress and the 'Digital Witness' hitmaker have recently been spotted together in New York, where they have been spending time together whilst Kristen promotes multiple movie projects at the New York City Film Festival.
A source said previously: "It's been very romantic. Kristen is always whispering closely in her ear and asking her opinion."
The news of Kristen's new flame comes after she recently opened up about her last relationship with on/off girlfriend Alicia Cargile.
She said: "Right now, I'm just really in love with my girlfriend.
"We've broken up a couple of times and gotten back together, and this time I was like, 'Finally, I can feel again.'"
And for Cara and Annie, the pair remain "pals", but called time on their romance after Annie failed to attend Cara's birthday party.
A source said: "The cracks were beginning to show on Cara's birthday in August when Annie wasn't there for her party.
"They decided to call it a day but remain pals and are hoping they can work things out as it's no doubt they really love each other."