"They do keep their relationship to themselves. I mean, they'll hold hands and they're affectionate but it's very tame," says Carrie Preston, who plays waitress Arlene Fowler on the hit show, which premiered its third season Sunday night.
But the love between Paquin, 28, and Moyer, 40, who got engaged last summer, is obvious, says another cast member. "You can see that this is a wonderful real friendship," Kristin Bauer, who plays the vampire Pam, tells PEOPLE. "There is just no way for them to have that not be evident."
Bauer says that in acting circles, especially, on-set romance is common, but her costars balance their work and their personal lives effortlessly. "That can be difficult but it doesn't seem like it is for them at all," says Bauer. "It feels like they're such professionals and we're all friends, so it feels very comfortable."
Plus, she says, they seem like they belong together. "They're just incredibly wonderful together and I just adore both of them."