Susan saw a lot. Not everything, but definitely a lot more than Peter gave her credit for, thank you very much.
She'd seen the fascination Caspian had for Peter. Oh yes, she saw how his feelings for her quickly vanished and she was replaced by her older brother. She saw how his fascination developed into obsession then settled into love.
She also saw something else in the glare Peter was always sending Caspian's way. Another layer of feeling in his eyes which betrayed a hidden longing.
They didn't say anything about it. They never told anyone the truth or betrayed much of what went on behind that locked door. But Susan saw it anyway.
Susan saw the looks they flashed at each other over breakfast and during boring council meetings. Susan saw the quirked eyebrows and rolled eyes they shared. Susan saw their identical expressions, that they didn't even realise they were pulling in unison. Susan saw how they snuck away early from the banquets. Susan saw all the private smiles meant just for each other. Susan said nothing.
Susan said nothing about the time she'd slipped into Peter's room early one morning and found the two kings naked and peacefully sleeping in each other's embrace. Susan had simply smiled and slipped out again. Susan saw the passion in their eyes when they looked at each other, the barely concealed lust which made her feel rather hot under the collar. She saw it and said nothing.
Susan made excuses for them. Susan lied to the court for them. Susan saw but kept her mouth shut.
Susan also made excuses for her younger siblings. Susan had less serenity over what they were doing but she had to admit it was sweet. At least they weren't fighting anymore.
Susan saw the way Lucy smiled at Edmund when he held her from behind to take her through the movements of a new sword drill he was teaching her. Susan saw how Lucy had worn him down and wangled him into teaching her swordplay, although it transpired she was better with dirks anyway.
Susan saw the way Lucy purred happily when Edmund kissed her forehead affectionately. He was allowed to do that because she was Little Lucy. True she wasn't that little anymore; four years had passed since they'd disposed of Miraz and disobeyed Aslan and stayed in Narnia.
Susan saw the satisfied smirk Edmund wore when Lucy sat near him in the evenings while he played chess or read. Susan saw the smug smirk he wore when the pair of them returned from a ride in the woods. Susan had said nothing. Well not quite; she had gone down to the stables shortly after the first ride and firmly told Phillip and Clara no to mention what their riders had been up to on those private jaunts to anyone, not even the other horses. Susan saw how delicately Edmund treated Lucy when he helped her mount or dismount her white mare Clara.
Susan saw how clumsy Lucy had suddenly become around Edmund, and how he always felt the need to catch her and steady her. Susan saw the way Lucy would lay a hand on Edmund's arm when he was getting worked up in a war council meeting and how it would instantly calm him down back to rationality. Susan saw how when Lucy would get peeved at some injustice, Edmund would calmly solve the problem before she shouted herself to bed with a headache.
Susan saw the way he read to her in the sunshine while her head rested in his lap and while her hands made daisy-chains. Daisy-chains which Susan saw her later make him wear.
Susan saw the way Edmund didn't get angry like he usually would when Lucy nicked some food from his plate or drank from his goblet. She saw how he didn't mind listening to her prattle on about her nonsense, when he used to humour her at best and ridicule her at worst.
Susan saw how Lucy slipped out of her room, the neighbouring one to Susan's own, to quietly sneak into Edmund's room at night after everyone was asleep. Susan listened out for that telltale creak of Lucy's bedroom door every night, smiling to herself at the indiscretions of her sister.
Susan saw how Edmund held Lucy's hand under the breakfast table and always made sure she got the choicest bits of food. Susan saw Lucy's blush whenever he mentioned a private joke of theirs. Susan saw how the younger girl's eyes shone when Edmund complimented her.
If Lucy's customary goodnight kiss, which she bestowed upon all of the kings and Susan, was closer to Edmund's mouth than his cheek, Susan said nothing.
Susan saw them kissing in nooks and crannies of the castle and said nothing. Susan saw the way Edmund caressed her cheek and said nothing.
Susan made excuses for both couples, not wanting to spoil their unconventional happy times. Gently she kept everyone else off the scent if the illicit loves of the kings and queens of Narnia. It didn't affect the way they ran the country, they weren't doing anyone harm, at least this way everyone's getting along; let them have their loves, wrong though they may seem. Susan saw it but didn't particularly like it, she disapproved of what her siblings felt for the ones they loved, but Edmund and Lucy were so indiscreet she had to watch them more closely if just to prevent other people finding out the truth.
Susan was discreet. Susan quietly tidied up behind her fellow kings and queens. Susan saw and said not a word.