Niall Horan's last night of his week-long takeover of The Late Late Show with James Corden came with the best surprise yet: a brand new "Carpool Karaoke" episode that tests the limits of his friendship with host James Corden in a number of exciting ways. To commemorate the release for his latest album, Heartbreak Weather, that officially dropped today (March 13), Horan had some hilarious fun while previewing the LP at the same time.

To kick off their trek to Corden's gig, Horan and Corden sang "Slow Hands" in an excited tone to set the mood of the drive. Then, things went left. They discussed Horan's fear of birds. With wide eyes, the singer explained why he stays away from pigeons. "I don't like the fact that they're not scared of us until you get really close to them," he said.

Instead of understanding and, you know, keeping Horan away from pigeons, Corden took him to a park where bird-handlers placed a few flapping avians on the singer's back. Corden grinned maniacally while Horan panicked and got pooped on. "James, I swear this has just made my phobia worse," the singer said when the ordeal was over.

They got back into the car and sang "Nice To Meet Ya" together and discussed Horan's time with One Direction. "Looking back, I realize just how lucky we were," the singer said. Corden agreed and reflected on his favorite piece of the group's merchandise, pulling out a container of toothpaste with everyone's faces on it.

After some more fun with songs like One Direction's "Steal My Girl" and Heartbreak Weather's "Put a Little Love on Me," the two ended the drive by testing their 10-year friendship with a lie detector test. Horan was visibly shocked and laughed incredulously, as would anyone if confronted with one out of the blue. The singer answered three important questions:

Corden: Do you believe that One Direction will get back together? 

Horan: Yes. (True)

Corden: Do you like Simon Cowell? 

Horan: Sometimes. (True)

Corden: What is your favorite late-night show to perform on? 

Horan: The Late Late Show with James Corden (False, actually Saturday Night Live)

After Horan gave Corden his own questions and found out that he's his favorite former member of One Direction (though he thinks that Harry Styles's "Sign of the Times" is a better song than Horan's "Slow Hands"), the trek finished, and their friendship was forever altered.

Check out Horan's full "Carpool Karaoke" episode up above.