The Try singer marked the age milestone on vacation in Bermuda on Thursday (28May15) and on Friday (29May15), she took to to reveal her longtime boyfriend Justin Young, who plays in her band, had proposed.

Alongside a photo of the couple on a boat, she writes, "This sweet man asked me to be his lobster... And I said yes".

The "lobster" quote is believed to be a reference to an episode of hit sitcom Friends, in which Lisa Kudrow's character Phoebe tells Ross (David Schwimmer) that Rachel (Jennifer Aniston) is his lobster because the crustaceans "fall in love and mate for life".

Caillat can be seen wearing a new piece of jewellery on her left ring finger in the sweet snapshot.

The couple has been dating for over four years.

In 2011, Caillat admitted she loved travelling everywhere with her "best friend", and claimed they were in no rush to wed.

She said, "I don't think there is ever a rush. If he proposed I would be very excited and I would be happy."