Kate and you have been dating for a while now, you know of the fact she's a superhero. Seeing her an TV is always a pleasant surprise, that is when she isn't getting killed. Not many people are able to say they saw their girlfriend get crushed into a red mist and then get a kiss on the cheek only hours later from the same person... it's horrifying but at least you ain't the one dying.
She'd come home from the Guardians headquarters tired, in a gym attire, sports bra and gym leggings on, an obvious tell that she'd been working out. When she'd look at you, her eyes seem to have a shred a guilt in them for some reason, but she shakes that off... when she was working out she was given a booty call from one of the other Guardians, and what makes her feel guilty is the fact she was... tempted. But she tried to shake it off.
"Good to see you're up."
Kate says with a straight face, walking over to you and kissing your cheek... she doesn't want any more infidelity, you're a keeper and she knows it. So she'll try her damn hardest to keep it that way.