Brad Pitt broke down in tears as he read a letter to Angelina Jolie in which he revealed his love and admiration for her.
The 'Moneyball' actor stayed by his fiancée's bedside when she underwent the first stage of a double mastectomy procedure to prevent her from developing breast cancer, and he poured all his feelings into a heartfelt note.
When Angelina - who was identified to carry the BRCA1 gene mutation which causes cancer - was too drowsy from anaesthetic to read the letter, Brad read it out to her.
A source told the new UK issue of Grazia magazine: "While she was sleeping, he stayed up all night writing her a letter. One of his biggest points was that he regretted not making an honest woman of her yet. He said the experience made him want to marry her as soon as possible.
"The letter was five pages long. Brad also spoke a lot of how much he admired her as a strong woman, for her humanitarian work, and spoke at length about how she would always look after him when he needed her. He promised to do the same for her."
The couple - who raise six children together, Maddox, 11, Pax, nine, Zahara, eight, Shiloh, six, and four-year-old twins Knox and Vivienne - are now preparing to marry on their South of France estate in July and want the day to be a celebration of their love and their future together.
Angelina, 37, and Brad, 49, have also chose tiger lily flowers to honour the actress' late mother Marcheline Bertrand - who died from ovarian cancer in 2007 aged 56.
The source added: "Brad, Angelina and the children are flying to the French Riviera soon to put the final touches to what is now being slated as an early July wedding.
"They've got Robert Procop-designed rings, and have a three-tiered chocolate cake on order and flowers including tiger lilies, which were Angie's mother's favourite.
"It's going to be a day full of love, laughter and focused on the future."