The 'Read All About It' hitmaker was married to the 'Made In Chelsea' star for three years until 2016 and admits it was a whole different world living with her in her Chelsea mansion.
He said: ''I nothing in common with anyone [in Chelsea] apart from the old eccentrics, who I loved - you know, passing me their spliff outside the pub. And parents who'd actually worked for their lot.''
And the 34-year-old rapper admits it was tough as he almost felt like he had ''to prove himself'' to some of her family.
Speaking about how his marriage to Millie gave him an insight into class divide, he added: ''In the same way it would if you married someone from a different county, because you learn about their culture, their ways, their history. Yes, because things that are normal to them are completely foreign. I've been in places and felt a bit like a novelty. Meeting certain people's family members and almost having to prove myself.''
Professor Green - whose real name is Stephen Manderson - is now happy with his girlfriend Fae Williams but despite posting a number of pictures online that hinted he was engaged, he insists he won't be announcing his engagement in that way.
He told The Sunday Times magazine: ''If I were ever to ask anyone to marry me again, I probably wouldn't be as crass as to post it on Instagram.''
Conversely, Millie and her beau Hugo Taylor announced they were engaged with a sweet post on the photo sharing site.
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