Seth is definitely more partial towards sleeping on his back, that's for sure. He never really lays on his side unless there is another person he is speaking to, somebody lying next to him sharing stories and secrets--whatever piece of information he happens to find so interesting late at night. He has a number of positions, though, and that almost always depends solely on his mood. He never coils himself up tightly in a bundle of blankets or layers--he's already warm enough, and he hates feeling constricted or limited in terms of space. So--really--you'll find him with his arms draped over his forehead and line of vision, laying on his back with his shirt pulled up making his abdomen slightly visible. You'll find all of his limbs spread completely, laying on his back with a pillow over his face. The constant variable being--laying on his back. Sometimes when he's a bored sort of tired, his arms will be crossed. He's also a light sleeper--with his his enhanced sense of hearing. But if someone wakes him up--he acts as though he's still asleep. He likes to gather and collect information, base on what he hears.
Seth is not particularly physical or intimate. He doesn't really like superfluous or excessive amounts of contact, not unless he knows the person really well. With Edward, we see him offer a sort of side hug and a high-five, another gesture affectionately denoted as a 'brofist'--... but he doesn't like hugging people much. He loves other people, he loves his friends, and he loves attending social events--but hugs aren't exactly his thing. With Bella---....that's a different story. But when there are family members and mutual friends, acquaintances from friends, he would rather not receive a hug from them. Not too big on hugs at all.
The prospect of "making out" is not exactly appealing to him. Quite frankly he finds it kind of gross.
Seth never refers [ referred ] to his father as ‘Dad’, or ‘my dad’. Not unless they’re alone. The only time he ever addressed Harry Clearwater by ‘dad’, was when he was at home with Leah, Harry, and his mother. In public, or with anybody else, he called and-or calls his father 'Harry'.