Clingy, uncharacteristically so. It feels like if he lets go of you, you'll disappear forever. So he'll bury his face into your neck, inhaling your scent, holding you close to his still-naked body, taking in the afterglow. His hands roam all his favorite spots on her body. If you ever try to leave his arms for whatever reason, Byleth will give a disapproving sigh before getting up to follow you like a lost puppy.
Once he finds the reason why you gotten up he'll just silently step in front of you and do it for you. Saying something like "You could have asked me I would have done it for you."
B = Body part (their favorite body part of theirs and also their partner’s)
He has no particular favorite, He likes all of you, However if He had to choose. Byleth would say your smile. When you express such happiness for anyone for anything He couldn't help but feel your happiness as well. He also likes that your eyes seem to smile back at him when you look at him.
He also likes that you look at him when he's over you He likes having your attention. It seems a little selfish but he's quite possessive of it. Which he tries not to impose on.
C = Cum (anything to do with cum, basically)
He'll never admit what seeing your face covered in his cum does to him.
D = Dirty secret (pretty self explanatory, a dirty secret of theirs)
When you're not here, and he misses you, he takes a shirt or a piece of clothing he stole from your room and puts his face in it, inhaling your scent. Sometimes, actually often, his hand will slip under his pants while he thinks about you.
E = Experience (how experienced are they? do they know what they’re doing?)
Yes, He basically grew up a part of a mercenary company. He's probably had a few sexual encounters.
F = Favorite position (this goes without saying)
Any position where you're holding him or looking at him. He likes your undivided attention and if he sees your attention drifting elsewhere he can kiss your lips.
G = Goofy (are they more serious in the moment? are they humorous? etc.)
He's naturally more serious but if you're joking around then he can't help it but smile or chuckle.
H = Hair (how well groomed are they? does the carpet match the drapes? etc.)
Sometimes. Honestly it's because he forgets not that he doesn't want to or doesn't have time. Byleth isn't really naturally hairy unless it's on his head despite his father being a relatively hairy man... Guess he inherited that from his mother...
I = Intimacy (how are they during the moment? the romantic aspect)
He knows how to have sex but romance he has no clue about. He only kisses you because he likes doing it and your lips feel good on his. Romance does not come naturally to him. If he is doing things like lighting candles or giving gifts he's probably picking it up from somewhere else. And Byleth likes to please to see that cute smile he loves so much.
J = Jack off (masturbation headcanon)
Byleth is still deciding whether or not he should or would want to jerk off when, if he could, he could just wait for you and (silently) ask for your attention. The tightness in his pants feels very uncomfortable, but the times he had it weren't nearly enough to satisfy him compared to what you do
K = Kink (one or more of their kinks)
If you ask him he would probably just tell you that he doesn't know.
But I feel like he would have a weird obsession with listening to your heart or trying to. Maybe it's because he doesn't have one himself. He likes that. He's the reason why it moves fast. He likes that if he fucks you hard enough or makes you ride him, you'll be out of breath, your heart beating out of your rib cage. He wants to hold you close until he hears it.
L = Location (favorite places to do the do)
Byleth honestly would do it anywhere where it's just the two of you, he'd rather just fuck you in his bedroom though.
M = Motivation (what turns them on, gets them going)
Byleth would never admit it, but when he feels that jealousy when someone else has your attention for a little too long that's when his hands find your hips and you feel his nose and lips press against the back of your neck.
Sometimes, when he hasn't seen you all day or all week, he will actively seek you out for some alone time.
N = No (something they wouldn’t do, turn offs)
You would not hurt or, Gods forbid, put a blade anywhere near you. No, He doesn't even want to imagine a blade cutting your skin. When he saw you cut your hands with a knife, He practically rushed to snatch anything that he could rap the wound up.
O = Oral (preference in giving or receiving, skill, etc.)
Byleth is a little rusty, but he is a very quick learner because he not only likes your taste and likes to please but also your reaction. The way he will mutter out an apology if he uses a little too much strength to pry your legs open, his pupils blown wide, his breaths heavy as he salivates in his mouth for your taste.
P = Pace (are they fast and rough? slow and sensual? etc.)
Byleth pace always fluctuates in bed, However, it always tends to drift on the rougher side which he tries not to do.
Q = Quickie (their opinions on quickies, how often, etc.)
Yes and no. He likes the idea of finishing inside you when he doesn't have a lot of time to spend with you. The problem is he always wants more after.
R = Risk (are they game to experiment? do they take risks? etc.)
Byleth will try anything you're willing to try and then afterward he'll just say "I liked it, It felt good."
S = Stamina (how many rounds can they go for? how long do they last?)
Byleth absolutely has the stamina to go for a while. The reason why he doesn't keep you in bed until he's finally done is because he has duties to attend to or because you can't go on anymore.
Honestly it's just that He doesn't have the heart to tell you that he's not satisfied with just one round, So until that happens, he is done when you're done.
T = Toys (do they own toys? do they use them? on a partner or themselves?)
Byleth wouldn't like toys at first, probably because they would be new to him, and he's not used to them, but he starts warming up to them and maybe even starts using them. Personally, he prefers to try to make you feel good on his own.
U = Unfair (how much they like to tease)
Despite sometimes teasing you; Byleth doesn't do well with teasing. Personally, I don't advise it. If he could Byleth What instantly flip you back over. Before you get a little too cocky for his liking.
V = Volume (how loud they are, what sounds they make, etc.)
The most you're getting is a quiet moan or two heavy breaths and shaky grunts. You though? He'll try to make you make noises.
W = Wild card (a random headcanon for the character)
Byleth has a lot more dirty thoughts than you'll ever know. Byleth's inner pervert is so closeted it's locked in a vault.
Byleth likes going out in the forest with you, especially when there is a lake with running water or a river if you ask to swim with him He will react to the idea of being naked with you but he will not oppose.
X = X-ray (let’s see what’s going on under those clothes)
Byleth is big and he is a shower, The kind of likes that he is, It's addicting feeling the tight squeeze as he tries to spear and bully his big cock deeper inside. He likes me more muscular than you. He likes that he could pick you up easily.
Y = Yearning (how high is their sex drive?)
Before, it was pretty low, but after he met you, it kind of skyrocketed to above average. It's like he's addicted to you, because in a way he is.
Z = Zzz (how quickly they fall asleep afterwards
As soon as you're in his arms Byleth tends to fall asleep faster when you're cuddling him then after you've had sex with him. You give him safety and comfort that no one else could provide.