Quinn didn't want to fall in love with Noah Puckerman. She had spent all year trying to avoid him so any feelings could be ignored.
But it was near impossible, even without speaking to him.
And Need You Now? Fuck.
She didn't want to cheat on Sam. She honestly didn't. But Puck...
So maybe that's why she kissed Finn. Because she couldn't cheat on Sam-not with Puck. She couldn't be with Puck at all. She didn't have a reason why though.
In all honestly, she would change it all. She would go back to almost having a family with him.
She couldn't get with him now though. Not after the way she treated him.
That's why she kissed Finn.