Selena Gomez and Justin Bieber not engaged

Selena Gomez's publicist has dismissed reports the singer is engaged to her pop idol boyfriend Justin Bieber after the teenage beauty was spotted sporting a diamond ring.

The young couple has been dating since last year (10), and Gomez took the Baby hitmaker as her date to a friend's wedding in Mexico on Wednesday (07Dec11).

However, a representative for the Disney star insists the couple won't be hosting a wedding of their own after Selena Gomez's jewellery sparked speculation Justin Bieber had proposed.

The spokesperson tells Us Weekly, "She is not engaged."

Justin Bieber, 17, has made no secret of his desire to wed and recently revealed he wants to be a married man by the time he is 25.