Cara Delevingne has reportedly bought St. Vincent a ring with the letter 'C' etched on it to show her commitment to her.

The 22-year-old model-and-actress has been dating the singer - whose real name is Annie Clark - for four months and recently had her lover's initials tattooed on her finger and, in another act of love, she presented the 32-year-old musician with the special piece of jewellery.

A source told the new issue of Grazia magazine: ''After getting the tattoo, Cara bought Annie a signet ring with the letter 'C' on it, just like the one she has. This is a different kind of relationship for Cara - she's had flings before but this is her first serious romance and she wanted to show Annie just how much she cared.''

Cara recently sparked speculation she and St. Vincent had split after uploading a quote on heartbreak to her Instagram page, but insiders say she was simply upset at being apart from the singer.

The source explained: ''Cara and Annie had such a lovely weekend together but then they had to spend more time apart last week and it really got to her.

''Cara couldn't hide her emotions. She's told friends she hasn't felt this strongly about anyone else before.''

Despite their hectic schedules, the pair are doing their best to spend as much time together as possible.

The source said: ''Annie visited Cara on the set of her new film 'Suicide Squad' in Toronto and Cara tries to go to as many St. Vincent gigs as she can, whenever she's had a break from work.''