The 35-year-old singer revealed the 45-year-old 'Stranger Things' actor wooed her by wearing a T-shirt with her name on it that he bought on eBay, after branding Lily's official merchandise as ''cr***y quality''.
She told the Daily Star newspaper: ''Ever since the beginning of my career - I suppose it's my self-hatred and low self-esteem - I presume no one would want to have Lily Allen written on a T-shirt
D''avid wasn't impressed with my last merch. He said it was hit was cr***y quality and he got some off eBay.
''We were on our first date in London and I went round to his place he was like 'Do you think I should wear this or not?' It was terrible. It wasn't even Fruit of the Loom and it was green. I was like I am sure I have never approved that.''
Lily and David - who started dating in August 2019 - have been quarantining together amid the Covid-19 lockdown and Lily has been cooking healthy meals to help her man lose weight.
She explained: ''I am trying to cook healthy for David as he is gaining weight and wants to lose weight.
''I am going to try and make some more healthy food. I made some scones this week but most of them have gone to waist and I'm going to make a pavlova with my daughter today.''
Meanwhile, David is smitten with Lily and the 'Hellboy' star previously quipped that the brunette beauty has a ''stunningly beautiful butt''.
He said of Lily: ''[I only have eyes for her.] Until she's turned away from me and I stare at her stunningly beautiful butt.''
The couple were first spotted together at London's West End last year, and later had their romance confirmed when they were seen packing on the PDA in New York in October.
And Lily accompanied David to the Screen Actors Guild (SAG) Awards in January, where he was nominated along with his 'Stranger Things' co-stars for Outstanding Performance by an Ensemble in a Drama Series, as well as the Outstanding Performance by a Male Actor in a Drama Series prize for his portrayal of Jim Hopper in the Netflix show.
Former Bengal Lancer Harry Sullivan, aka From The Tiger's Mouth, has just released his first solo single - 'Morning News' under his new moniker.