So when her engagement was announced and the date set for mid-June, we all assumed, given their relationship, that the iconic designer would create her wedding dress.
Indeed all the fashion magazines announced months in advance that her gown would be a Chanel creation, and the singer personally confirmed the news after making various trips to Karl's Paris headquarters.
We couldn’t have been more surprised then when the 26-year-old unveiled her wedding dress a couple of weeks ago at her Gloucestershire country ceremony: of course she looked fantastic but the dress just wasn’t what the fashion pack expected.
The design, an empire-line gown with a spectacular Twenties’ style veil, wasn’t by the 'fashion Kaiser' but was instead the work of French designer, Delphine Manivet.
The demure dress – which featured long lace sleeves, sweetheart neckline, lace overlay and a fishtail skirt – gently skimmed over her body to reveal her baby bump. Her husband Sam Cooper later revealed much to the delight of their guests that Lily was four-months pregnant.
So what happened to the Chanel gown we were all expecting? A few days before her wedding, Karl Lagerfeld had uploaded a sketch and a photo of the singer wearing one of his creations during a dress fitting in his Paris studios – so when she walked down the aisle in Delphine Manivet we were all left slightly confused.
However Lily, a keen Tweeter, quickly explained that she had worn her ‘beautiful Chanel dress at the reception’. The design – vintage-inspired with puffy sleeves from the shoulder to the elbow, an empire-line chiffon skirt and embroidered detail around the neckline - suited Lily’s style perfectly and she looked every bit the radiant bride.