So we're a little bit worried at the news that they might be forced to separate for a while when the rapper heads to the US for his work.
The East End star told heat! magazine that he's heading to the States indefinitely once festival season is over.
[Related story: Millie Mackintosh shows off her amazing bikini bod]
[Related story: Millie Mackintosh gives us a lesson in festival fashion]
He told them: ""I'm going to the States to record my new album. I haven't put a limit on things, so I'm not sure how long I'm going for, but I'll be there for a while from September.
"I'm going to be all over the place — New York, Atlanta and then LA. I'm working with exciting producers, but I can't say who."
Asked if he'll miss his girlfriend of eight months, Made In Chelsea's Millie Mackintosh Pro replied, "Of course."
We're hoping that Pro Green and Mills are strong enough to see the long-distance thing through.
And perhaps the MIC star might even join her other half on his American adventure.
The pair hit T4OTB together this weekend and last week, Millie supported her man at the Isle Of Wight and Hackney Weekends.
Mills showed us exactly how to do festival chic by showing off her amazing figure in tiny cropped denim shorts and wellies.
Meanwhile V Festival organisers are predicting that the pair will be the most loved-up in the Virgin Media Louder Lounge come August.
This week's heat, with free 'heat extra: TV & Pop special' is on sale now