Who sings ow in heart attack by one d?

Question

Ok so I love the song heart attack by one direction but who sings ow? It says all sing it but my friend said it was niall. So now ok confused. I also think its kinda funny!
Once you answer can you leave who sings it how you know and if you think it's funny in the song how it sings ow!
So maybe like this**

Well I think Niall sings it. I looked it up but you never know. It could be a rumor, and yes. I think it's really funny how they say that. But i guess it goes in the song.
Please don't copy above... That was an example. Only leave true answers please

Answer 1

I also think it sounds like Niall and some lyric videos say it is him as well but recently I heard that the person who says OW! is actually Paul (I don't know if you know who that is). I think it is Niall though so...yeah...Lol!

Answer 2

Who Sings Heart Attack

Answer 3

Of course it's niall

Answer 4

I believe it is Niall