Jennifer Aniston has gushed that she is knocked out by fiance Justin Theroux's looks every day.

The former Friends star has been with the actor for around three years, but revealed his appearance still takes her breath away.

The actress spoke out at a dinner in Justin's honour hosted by Details magazine, telling Women's Wear Daily: "He's just so beautiful and handsome to me."

Discussing the cover of Details, which Justin appears on, she gushed: "I love that his eyeballs are so beautifully captured because those eyes just knock me out every day.

"He just gets better every year. He's just like a lost gem in the sand, and he's just always been there and been brilliant, and now this is just in a different light."

Jen, 45, also commended the Leftovers star, 42, for "his courage" in becoming a cover star.

"This is not normal for him," she said. "He's so graceful and utterly kind and golden."

The couple were joined by celebrity friends including Jen's pals Chelsea Handler, Mary McCormack, Malin Akerman and her former Friends co-star Courteney Cox, who was at the bash with her own fiance Johnny McDaid.

Courteney said there was "no better cover boy" than Justin, adding: "H e's so handsome and cool."