Evangelion

Was she serious, user?

Yes. The doujins of that are pretty hot.

But why would she do it?

Why not?

Misato's not adverse to using sex appeal as motivation, but Kaji's dead and gone, so yeah, if Shinji had gone out there and saved the fucking world, again, she'd have fucked him senseless as a thank you. She'd probably tie up Asuka and make her watch as well.

she was just joking about it since the first episode haha she just wanted some laughs

There are a few contributing factors. She's a slut, She likes a good dickin' when stressed out, it was foreshadowed all the way back in the beggining of the series, there's definitely a degree of "tension" between them already - in no small part due to the fact that She only knows how to connect with ppl She cares for through her orifices.
The world was about to fucking end, and if that little Cuck gets his shit together - perhaps it won't.
She going to probably die, SOON - anyway.

>Tl;Dr: She has nothing to lose anymore, and a part of her is undeniably salivating at the prospect. Would He actually succeed - then at the very least, he's getting his dick sucked out of that deal.

>Shinji netorared Misato
>confirmed months of she masturbating to Shinji
>Kaji is the biggest dead cuck ever
>all this without even putting his dick inside of her
>after barely a glance and not even to his full erection
Now imagine the size of Shinji's big cock.

No, she was lung shot and dying

I'd have to say no, not because she wouldn't do it, but because she clearly wasn't going to live to see him come back anyway.