( For the misunderstandings, I know it can be hard to phrase things over the internet, so I did ask two other people to look at the asks before I answered them to be sure of my interpretation. I’m not trying to snip at anyone, I just want to make sure we’re all on the same page. I dislike conflict to the point that I’m more likely to hide than answer if anyone wants to start a fight, as neon can attest to. )
Sam and Dean both have very strong personalities. It’s inevitable that they will clash at some point or the other, and this has actually already happened in the stories a few times. Misunderstandings, as well, arise when there’s such a huge discrepancy in size.
In Shadows and Reflections, they spend most of the story misunderstanding each other, the Second Interlude, of course, Sam feels like he’s being ignored and he has no way to leave on his own, and the big argument goes down in The Schism of Fire and Water when Dean feels like he’s being ganged up on and forced to do something he is absolutely against. A byproduct of these arguments is the fact that Dean is indeed over 115 feet tall from Sam’s point of view. If you see someone that size getting mad at you, you’re going to be intimidated, especially near the beginning of getting to know them again.
Over time, Sam’s getting better at both realizing he’s fine no matter how pissed off Dean gets and hiding it if he does get intimidated. There will always be arguments between these two, because what two brothers don’t fight? However, the dynamic of the fights will continually change as well depending on how their relationship is doing at the time.
Of course, Sam’s current solution to Dean being ornery is sitting on him until he talks, which worked pretty well considering Dean doesn’t want to just snatch his little brother up. He is pinned.
A brief look back at The Schism of Fire and Water to remember the most volatile fight they’ve had:
Practically growling, Dean sat back. “I don’t like this. How are we supposed to kill Ilyana if she’s in a container this big?” He held his hands spaced about two feet apart. “I can’t exactly shoot her without shooting through the container and that ruins our entire play.”
Bobby and Sam shared a silent look. Either Dean was the only one who hadn’t figured it out, or he was desperate for another option…
“Dean…” Sam said quietly. “It has to be me. I’m small enough to be trapped with her. I can do it.”
Dean’s eyes lit with anger, glancing between Bobby and Sam with a look of betrayal. “No.”
Bobby tried, “Dean…”
“No!” Dean stomped to his feet, slamming his chair in against the table angrily.
Sam was knocked from his feet, landing on the table next to Nixie with a fearful look in his eyes at the huge, angry human. He’d never seen Dean like this before. He took a shaking breath. He could do this.
Sam scrambled to his feet again. “Dean… it’s the only way. You know I can handle it.” Sam gave Dean his most pleading look.
Bobby joined in with Sam, trying to calm the other hunter down before he did or said something he’d regret. “Dean, I’m just as worried for Sam as you are. But you know as well as I do he’s more than up to the task.”
Dean backed a few feet away like a cornered wolf, almost snarling at Bobby. “Hell no! I’m not signing up for my brother’s funeral! As soon as he’s trapped with her, he’s at her mercy! She already tried to blow him up!” He paused, staring straight at Sam with a dangerous glint in his eyes. “Or worse. She doesn’t blow him up. She grabs him and zaps them both off to god knows where and we never see him again!”
Sam was shaking his head. “Dean, she’ll be trapped. She can’t just ‘zap off’ with me the way she wants to. This will work.” Sam put all of his emotion, all his trust into that sentence. He couldn’t convince Dean if he couldn’t convince himself.
Dean wavered. Sam could see it in his stance, the way he held himself uncertainly. But before Sam could call himself victorious, the glint in Dean’s eyes hardened again. “No. I’m not offering you up as a sacrifice. We’ll find another way,” he growled, stomping over to the table. He put his hand down right next to Sam. “We’re leaving, Sam.”
Sam stared at the hand like it was a snake. Dean saw his hesitation. “Well? Aren’t you coming?” he snapped.
Sam edged away from him, towards Bobby. Surely Dean wouldn’t just grab him up. “No… I’m going to stay here and do some more research.”
Past the anger in Dean’s eyes, Sam saw remorse and betrayal. Like Sam had taken a chunk out of him in his refusal. Please… you have to understand, Dean. I need to do this.
I’m the only one who can.
“Fine,” Dean growled. He stomped towards the stairs. “But don’t expect my help if you plan on using my brother as bait!”
A door slammed upstairs, rattling the table. Sam’s shoulders slumped, amazed at the amount of fear he’d felt at the unexpected anger from Dean.
Remember, that’s an angry Dean Winchester, over a hundred feet tall! Not many people could stare him down and win at that size!

I think Sam’s method of dealing with him is pretty effective, all things told…

Wonderful art by @little-miss-maggie!