While neither Harry nor Taylor has said that they're dating, we'd say their constant NYC hanging out/holding hands/kissing and the couple flying to London over the weekend makes it pretty clear that Haylor is a thing.
Olly, however, didn't beat around the bush about Taylor and Harry's dating status.
Watch Olly play a little game of "Kill, Marry, Snog," where he says since he's "not a killing type," he picks one woman to "avoid" instead of knock off--Taylor!
Olly explains, "because she's dating one of my friends. She's going out with Harry Styles. So, Harry, I couldn't obviously go near Taylor 'cause that's his missus."
Haylor = confirmed!
In other less confirm-y news, One Direction bandmate Louis Tomlinson has given Taylor his seal of approval, telling Huffington Post, "I've met [Taylor] before and she's a lovely girl."
He did note, "I'm happy that they're good friends."
Uhh...we're pretty sure Harry and Taylor are more than friends.