Justin Timberlake fell for Jessica Biel when she was the only person who laughed at his ''sarcastic comments''.

The 37-year-old singer has been married to 'The Sinner' actress - with whom he has three-year-old son Silas - since 2012, and has said the first time they met at a party in Hollywood, he found her ''undeniably beautiful'', and was shocked by their similar sense of humour.

Writing in his memoir 'Hindsight: & All the Things I Can't See in Front of Me', he said: ''When I met Jess, it was undeniable how beautiful she is. I made some sort of sarcastic comment, really dry,'' he explains. ''Nobody got it except her. She laughed, and I noticed, all of a sudden, and in the way where you wonder if a person's like you, if they have a very dry, dark sense of humour, too.''

The 'Can't Stop The Feeling' hitmaker didn't ask for Jessica's number during that party, and had to ''give himself a pep talk'' in order to gain the courage to speak to her again.

He continued: ''[I kept thinking] I'm kind of really interested in that girl. There was just something about that girl. Kind of interested in that girl. Goddamn it.

''I had to psych myself up. I had to remind myself that I was me - giving myself a pep talk, shadowboxing with myself, rubbing my own shoulders.''

The pair met again when Jessica, 36, came to a show during his 'FutureSex/LoveSounds' tour, where he finally asked for her phone number and began talking to her more regularly.

Justin wrote: ''Then the Golden Globes came up, and that's when we planned on seeing each other. We were both still seeing other people, keeping ourselves safe from getting hurt, from really putting ourselves out there. It took a bit for both of us to admit to ourselves that we were really, really into each other.''

The 'Say Something' singer then headed out on tour, and when he returned, the pair spent a month together, during which time they decided to be exclusive.

Justin penned: ''We've had a lot of unforgettable times. She's become a huge influence on my life, and I have such an admiration for her, especially seeing her as a mother now.

''But I had admiration for her before. She's a very good writer. She's a poet. She's a tremendous actor. She's funny. Very funny. And she's one of the most patient people I've ever met ... She changed me. She changed my life.''