United Kingdom, April 12 -- Sir Mick Jagger is engaged to Melanie Hamrick - but they haven't made any wedding plans yet.

The 81-year-old rock star and Melanie, 37, have actually been engaged for "two or three years" now, but the choreographer has admitted that she's "too afraid to change anything" about their relationship.

Speaking to the French magazine Paris Match, Melanie shared: "Maybe one day we'll marry, maybe not. We are so happy in our current life that I would be too afraid to change anything."

The loved-up duo first met in February 2014 when they were both on tour in Japan.

Asked if they had an immediate spark when they first met, Melanie replied: "Maybe a spark, but nothing incredible, like, 'Come on, I'll blow your mind an...