He had met her when Thor dragged his Precious Jane to a Gala Event for Shield, and both Darcy Lewis and Eric Selvig had tagged along. It was the first time he had seen her in something other than Hoodies and Jeans, and she was stunny, clad in Blue, looking fancy but comfortable.
He had struck up a conversation, pleased to meet someone who could keep up with him mentally that wasn't a giant green rage monster, and one more drink led to one more drink led to one more drink, and before he knew it, they were fucking, in the bathroom, except for this time, he took her home afterwards, and kept her there the next morning, and made a semi-respectable breakfast, and gave Pepper orders to let her stay as long as she wished.
The words I love you didn't usually pass Tony Stark's lips, he reserved them for Dum-E and Butterfingers and U. But after their… 8th time? 8th Time in his bed, he looked down at the sleeping scientist, and brushes hair from her cheek, and whispers the words, finds he likes them on his lips in relation to her.
One day turned to two turned to a week turned to a Sure you can keep a toothbrush and some clothes here turned to a Month turned to a few months turned to I want you to Marry me turned into a Honeymoon in Africa turned into I think I'm Pregnant turned into a swollen belly and I think i felt it Kick and Its a Boy and turned into worries about being a parent, turned into Stop worrying like that everything will be fine.
Turned into Now he's 75, and he has a Son who has a Wife, and and a small Grandaughter turns into watching the woman he loves pass on turns into whispering I love you against her lips one last time.