Louis Tomlinson wanted to forget everything, so he went to a pub.
Harry Styles had just turned 18 and wanted to celebrate, so he went to a pub.
Neither expected to wake up in the same bed naked. It was a drunken mistake. It didn't mean anything. It wasn't supposed to turn out like it did.
After awkwardly exchanging phone numbers they went back home. Neither communicated with the other, they didn't have a reason to.
Two months passed and Harry started feeling sick, so he goes to the doctor. He didn't expect to be told he was pregnant.
(Description sucks, but I promise it will be better than it sounds)