Sleepover party! Taylor Swift and Ed Sheeran spend night together in London

Maybe it was that Tom Odell date night goss, maybe it's just that Haylor fans don't want to believe Harry Styles and Taylor Swift will never ever (ever) get back together. Or maybe the hotel staff finally got around to looking up E! News' e-mail address or something. But get this: Taylor Swift and ! Ed Sheeran threw themselves a sleepover party the night before the BRIT Awards (Feb. 20), and though the world is only hearing about it now -- two weeks before they launch their North American tour, just saying -- let's all jump on this hook-up rumour like Harry Styles on cougars and start picking out their couple name.

Sweeran?

Sheeft?

We'll keep brainstorming while you read this account from E! News' source, who spotted Sheeran arriving at Swift's London hotel Feb. 19, where, the source says, they "stayed in the room, just the two of them, until around 4 a.m."

"He looked very pleased with himself," the eyewitness says of Sheeran, who reportedly looked "very happy" as he left the hotel, driving away in the hired car Swift was using during her BRITs visit.

But whatever could they have been up to all those hours, without a trampoline or pantry of baking supplies between them? (Please recall Swift's story of how their duet,! Everything Has Changed came to be because somehow it's hard to forget that two of the world's biggest pop stars bond over baking pies and playing in the backyard like a couple of "eight year olds." Swift's phrasing, not ours.)

But if, as Swift once told MTV, "the combined maturity level of both of us is eight years old," maybe this hotel hook-up was less "sexy" sleepover and more sleepover-sleepover, complete with cookie dough-binges, pillow fights and maybe some Legos, just for Sheeran's sake. (Also: business. As previously mentioned, these two have a North American tour to consider, one that will span from March to September.)

Swift, 23, and Sheeran, 22, "briefly dated last spring," one snitch tells E!. "He thinks she's really cute and they have a great chemistry together."

But it's more widely known that these two are solidly in the friend zone. When Sheeran's phone went missing at the BRIT Awards, there were stories about how Swift freaked over who might have swiped it.

"Someone's gonna get videos of me having a conversation with my cat that I sent Ed," she told Capital FM. Illicit cat videos? Finally, a celeb hacking scandal that would make the world a better place -- while also, potentially, being more viral than a sex tape. There is a reason why Taylor Swift is a superstar. This is it.

But cutie-pie best friends can turn into cutie-pie more-than best friends. Maybe, as they sing themselves, Everything Has Changed.

All that's certain is there are plenty of warm and fuzzy feelings between these two.

Check out our 9 favourite Swift/Sheeran quotes.