For The Love of GOD I NEED HELP

Ok the song says something about:

"You have her picture eveywhere"
another line refering to stitches and them falling out at the end it says:

"or maybe she's the one "

the music video includes a nerdy guy and a goofy girl. It really is cute and i remember a scene in which they're doing a race but they haev to keep their lips pressed together.

If anyone can help me I'll love you forever, this is driving me to the point of insanity.

if it helps I think Sia, sings it.

OMG PLEASE SOMEONE HELP ME. eveyrday I die a little more not knowing the song. (not really, but still help!)