Pepper can appreciate what and who Tony is.
She can do that if only because he has changed himself so that the title of Merchant of Death is obsolete. He has changed himself enough that she is not paid to escort women off the premises. He has changed enough that his lab and his alcohol stash do not take away days at a time.
He has changed enough to realize that Pepper is a privlige. But Pepper has changed, too.
If, ten years before, when she was just starting work at SI, that she would become CEO and bed a superhero, she would laugh in your face. Now, if it wasn't already true, she would accept it like that.
Deep down, on some remote level, she knew she couldn't live without him. She wouldn't know what to do without his constant snark and endless thought streams. But he wouldn't know how to live, either.
She ran his life - he cemented hers.
...
Tony can appreciate that Pepper has not left his ass. She has every reason to.
He's an alcoholic. His job nearly kills him everyday, even when he's not in the field. He put her through years of doing stupid, small and (in relation to her actual skills) derogatory errands for him. He has, like, eight friends, and of them, there are maybe two that do not infest his tower with their doom and gloom.
Pepper has pushed him right on through every problem he's encountered, and... that meant a lot to him, okay? He'd grown up with one person giving a fuck about him and his problems, and then that person had died, so years of being ignored lead up to practically imprinting on anyone that paid him any mind.
So. Imprinting. He wasn't that far gone, he hadn't actually imprinted, but he was seriously doubting he would love anyone the same way he loved Pepper.
Because, yeah, he freaking loved Pepper.
(Was that supposed to be scary, or...?)
