How would the DnD boys be like with each of the possible character sizes like tiny small medium
Like would they let a tiny sized reader sit on their shoulders or a large end species like a Goliath hold the them 
Well, technically the boys are medium creatures despite still being so TALL. So, they are still pretty big for medium sized creatures.
I think for tiny, it's a lot of them wanting to hold you in their hands. It might be rude, but they like holding you and bringing you up to eye level to check you out. They don't want to squat to talk to you, it feels rude. (Even if holding you up also feels rude, but they at least get to hold you and see you nicely.) They are very nice about letting you ride around on them wherever you please. They try to be respectful, but you are so cute and tiny. They really adore this size. I usually imagine a winged reader for tiny. Probably scares the pants off of Soleil when they fly around, but Atlas is mesmerized.
For small, I don't think they pick you up as much unless you ask. It feels even ruder at this size. So it's a lot of them looking awkwardly down at you or them simply sitting down on something low to talk with you. They still think you are cute, but more boundaries are put up. You are still a person (or if you prefer, creature,) so they would like to not upset you by being asses about your size. They touch your hand a lot with theirs' being so large. It feels connecting.
Medium is just how they regularly interact! Everyone is still small to them, but they grew up that way. It's no big deal.
Large is fun. They aren't used to being smaller than others around them, so if reader is in the large creature category size, they feel kind of, bashful? It's strange to have someone look on the top of your head or look down at you so much. They aren't used to it except Atlas with Soleil. But it makes them a little weirded out, like you shouldn't be so large around them. But they are still our sweet boys, and Atlas is still going to try so hard to flirt you down to his size. It's a silly dynamic.
Huge, they are just speechless. How can they talk to you when they feel like mice? It's like me being enamored by a giant woman. They are in awe of your largeness. Soleil kind of wants you to lick him and he's not sure why. Atlas still wants to flirt, but how can he talk himself up with you are already above him? Struggling guys.
And lastly, Gargantuan. I don't even think they'd try. That is TOO big. You'll crush them. They wouldn't know what to do. Now they know how tiny creatures feel. It's very vulnerable and they don't like that. You'll get hellos and thank yous if you are kind, but besides that, they keep to themselves with someone that big.
