Amy Adams' fiance Darren Le Gallo once serenaded her with the theme song to St. Elmo's Fire before she was due to shoot a sex scene with the film's star Rob Lowe.

The Fighter star had to film an intimate moment with one of her personal idols, Lowe, on his short-lived Tv show Dr. Vegas, so Le Gallo attempted to break the tension by singing the theme song to the heartthrob's 1985 drama.

Adams tells Vanity Fair, "Here's how great Darren is - I don't think I've ever told anyone this story. On the day I had to shoot a love scene with Rob Lowe, he called up and sang the theme song for St. Elmo's Fire. He is in it. That's how awesome he is.

"I remember it was my 30th birthday too and my sister was on set, so it was very strange. And I grew up loving St. Elmo's Fire I thought that's what it meant to be an adult. You went to bars and you had lots of drama and you had to buy sofas and it was all very dramatic."

Adams and Le Gallo have been engaged for the past five years. In 2010, they welcomed their first child, daughter Aviana.