He thinks about her in ways he shouldn't.
When he met her, he was with a girl he can barely remember now. Theirs was a polite, faintly distant relationship: he held doors open for her and made her come twice before he came once, and when his mother asked if they were serious, he said yes.
He'd spent a lot of time looking for girls who weren't like his mother, and trying to convince himself he was nothing like his father, and that someday he'd have a marriage that didn't involve plates shattering against kitchen walls or screaming matches at 6 AM. This girl fit pretty well into his mental image of the home life other people had.
He wishes he could remember her name. She's dead on some forgotten colony moon, and it seems rude to forget her so utterly.
(Lee is never rude.)
When he met Kara, she was lounging in the corner of a booth in an off-base bar, and Zak was looking at her like she glowed from the inside.
She did.
Lee had the girl he can't remember with him, and the four of them made polite small talk, and Lee knew that Kara and Zak were holding hands under the table. It bothered him. His relationship with the forgotten girl had no secret corners, nothing he can't tell his mother. They didn't touch in public, ostensibly because such things are gauche.
He broke up with her two days later, very politely, with many assurances that it wasn't her, it was him.
A week or so after that, Zak came over for dinner, and brought Kara with him, and Lee stared at the two of them and couldn't understand why she belonged to his brother.
He was, for the first time in his life, profoundly jealous. It was new to him: Zak and Lee had never been competitive. Because Lee had already won: he was the smarter faster older one, the hotshot pilot, the boy their mother loved best, even if the father did not.
Kara didn't even notice him.
In the kitchen, Zak told him that they were engaged, and Lee rummaged around needlessly in the fridge until he had his face under control.
"Congratulations," he said.
"You don't—you don't approve?" Zak asked.
"You don't need my approval," Lee said, and his inflection was so precisely that of their father that he totally overdid it in covering up and going on and on about how happy he was for them.
Zak seemed to buy it. Kara looked at him funny a few times, but Kara, like Lee, didn't show much. They had different ways of distracting people from the truth, but the end effect was the same.
When Zak died, in the split second before he thought- my brother, my mother's son, my father's child, gone, gone, dust, he thought- Kara.
And not, Kara, my almost-sister-in-law.
Not like that.
Years later the four of them are rolled up in a tangled knot he can't hope to tease apart, and it cycles back and forth Kara/Lee/Zak/dad until he doesn't know who's who and what's what and if the scene he's replaying with Starbuck is from his childhood or hers. It seems like Zak should play less of a part now that he's dead, but he doesn't.
And Lee, who is honest with himself even if with no one else, admits that maybe about a quarter of why he wants her so much is because it's the last way in the universe he can touch his brother. That's bad, but it's the rest of it that makes him drink.
When they finally run out of booze, he finds the weight room and works to muscle fatigue and beyond.
He is an honorable man, people think. But he knows the truth.
He thinks about her in ways he shouldn't.