very normal human behavior
Tommy has a secret. No one knows. Not the nice lady at the corner store, not the weird guy at the video game store, not Tubbo, and certainly not any of his housemates. He's an alien, sent to study Earth. It's not easy, keeping that secret when he's living with three humans, but he can do it, he's sure.
Wilbur has a secret. He's not told a soul and never intends to . He's an alien, sent to study humans on Earth, so that his people can make first official contact. It's not easy hiding what he truly is, especially when it comes to his three human housemates.
Technoblade has a secret. He's very good at keeping it, but sometimes it's... difficult, around his three human housemates. Loathe as he is to admit it, Technoblade cares about them, and perhaps even feels guilt over his lies. His race wants him to determine whether or not Earth is an ally or an invasion site. But, for the sake of his people and new friends, he will keep his secret.
Phil does not have a secret. He has never, once in his life, kept his mouth shut, even when Puffy tells him to. It's not his fault no one else believes aliens exist. At least his new housemates, normal as they are, seem to tolerate it better than the last guys.