Katy Perry has been spotted with a ring on her engagement finger.

The 'Roar' singer was pictured with partner John Mayer on Valentine's Day (14.02.14) sporting a ring on the third finger of her left hand, making many wonder if he had asked her to marry him.

The couple enjoyed a meal at Sunset Towers in Los Angeles on the romantic day before heading to a club to party.

A source told E! news despite the ring they are not engaged yet, but ''they are really happy. They had the most amazing date night. They had a private booth at Bootsy Bellows and were very happy just to be together.''

Another source told People.com Katy was sipping champagne in the club and at one point stood on a sofa at her table and dancing to Montel Jordan's party track 'This Is How We Do It'.

Superstition has already pointed to Katy - who was previously married to comedian Russell Brand, who she divorced in 2012 - and John marrying, after she caught one of the bouquets of flowers thrown by a couple married during Macklemore and Ryan Lewis' performance of 'Same Love' at the Grammy Awards. Tradition follows that the person who catches the bouquet will marry next.

Sources have also said John referred to Katy as his ''wife'' when they were on set for a joint TV appearance last year.