The "Love Story" singer and the actor - who have been together for four years - were forced to stay in the U.K. due to coronavirus restrictions and are said to currently be living in a $7.5 million (£5.5 million) abode in the north of the city, which they are renting from an unnamed British rock star.
"They keep things extremely quiet together, and apart from Taylor's song lyrics nobody ever really knows too much about how well things are going," a source told Britain's The Sun newspaper. "But the fact they've decided to share a home for the first time is a pretty clear sign that they're the real deal now."
"They've been there for most of lockdown. Taylor doesn't think jetting around the world is the right thing to be doing. She wants to stick to the rules, and doing that together just made sense for them. She's still got her homes in the U.S. too so she hasn't left there permanently. But this works for now and it's the first time they've really had a place just for the two of them."
Despite their fame, the couple - who were recently spotted on a walk around a local park - have managed to stay low-key and been unnoticed by their neighbours.
"They're actually really normal, they drive around in a really low-key car and just make the odd trip out to go for a walk," the insider added. "You'd never know one of the world's biggest superstars was living there."