Laia Costa, who plays Libby in this week's episode of Soulmates, talks about what drew her to this project, why Libby isn't as confident as she seems, and how Libby's honesty borders on naïveté.

Q: What drew you to this project?

A: I loved the idea of a six-episode TV series revolving around the same concept. I was a big fan of the creators Brett [Goldstein] and William [Bridges], and I was really excited to work with Marco [Kreuzpaintner], who directed my episode. I had seen his work and I think he's truly talented. So the creative team was really appealing to me, and the idea of this umbrella concept for all six episodes I thought was very interesting.

Q: Libby clearly knows what she wants from her partners and relationships. How do you think that impacts those around her?

A: I wouldn't say so actually... I'm not sure she's that confident about what she wants. I think what makes her unique though is her courage. She seems to have some calmness when facing new dilemmas, like open marriages. For me this is a very tough issue. But I think for me it's because I have fears, insecurities about behavior that's not the norm. Libby, on the other hand, is able to face these circumstances with no fears. So I'm not sure if she actually knows what she wants, but the way she faces that is really different from what most people would do.

Q: Libby was the main driver in her and Adam entering into an open relationship. Is this purely a selfish act, or does she think he'll also be happier?

A: I think she's totally honest about her feelings and she shares them with Adam with total transparency. She's not keeping something for herself. I think there are absolutely no secrets between them, and I think Adam is totally attracted to that confidence in her and it makes him feel safe. She's not two-faced. She has no dark side and there are no terrible surprises with her. I think she believes Adam is smart enough to speak for himself, and that if he doesn't like something, he won't go along with it. I think Adam is happy with their open marriage in the same way Libby is, as long as they follow their rules.

Q: Does Libby really think there’s no way they could fall in love with someone else?

A: I think she totally thinks that. I mean, she's always, always, always honest about what she says. It's kind of a childish point of view, but at the same time, it's amazing if you're able to be that way. I think that's one of the most attractive things about her.

If she says they won't fall in love, she truly believes it—and to be that naive and transparent... that really helped me understand Libby. I think sometimes we think that if we're one hundred percent honest, that situations will be better and problems will disappear. It's very difficult to be honest all the time, and would it really work out better in the long term or not? In this case, it's really interesting to see that even when you're able to be so honest and so transparent about what you think, sometimes it still doesn't work out. There's always going to be something that makes your world a little bit more complicated.

Q: When Adam asks her not to sleep with her soulmate, Miranda, she avoids promising him that she won't. Is this because she's already feeling something for Miranda?

A: I think deep down inside, Libby's very attracted to Miranda. She's a big question mark for Libby. What surprises Libby at that moment when Adam asks her not to sleep with Miranda, is the way Adam demands it of her. Maybe it's the first time he's upset about their way of doing things, the first time he actually sees a dangerous situation getting close. Libby's not feeling that way. She's absolutely fascinated by Miranda and she would love Adam to be as fascinated as she is. So it's a complicated situation, because it's a couple looking in opposite directions at that moment.

This is the first time they're not looking at a situation in the same way. And one is surprised that the other one is not surprised by that. Adam's like, "This is dangerous," and she's like, "No way. It's like all the other affairs we've had. It's totally fine." I don't know to what point Libby is kind of like lying to herself, but I think, if that's the case, it's in a very unconscious way. I mean, she doesn't want trouble in her life. That's not the way she is. She's not looking for drama, just the opposite.

Q: Libby chooses Miranda over Adam. Why do you think that is?

A: That's the thing... that's a bit of a trick question, because I wouldn't phrase it that way. She might have preferred the option of not choosing. She may have wanted to be with both of them. She's not saying, "I am done with you, Adam. I don't want to be with you anymore." Not at all. She loves him, but when Adam forces her to choose, he's actually forcing her to make a decision—a three-sided relationship is no longer an option for Adam. He has that right to make that decision, but I'd say that by doing that he's pulling himself out of the equation, so Libby has no choice really.

Q: If Libby’s soulmate situation proves anything, it’s that people can destroy relationships even if they’re scientifically proven to work. Why is she so understanding of Miranda’s relationship limitations?

A: I think it's because Libby's able to understand her point of view without feeling attacked by it. She's so open-minded, because her first emotion is always to trust the other person with no judgment. She doesn't take it personally. She's an ally, not an enemy, in any kind of relationship she's in. I don't think it's a conscious process for her. Like I said before, her perspective is kind of like a child's—she's not contaminated by social rules, mistrust, fear. This aspect of Libby was very difficult to play out, because usually, as human beings, in these kinds of situations we're weaker emotionally. It's very hard for us to think about someone else's feelings when we're so focused on how we feel ourselves—there's fear that this person is going to hurt me. Libby doesn't want to hurt anyone, so she doesn't fear anyone hurting her.

Personally, I've never known anyone like that. At the beginning of filming, I was like, "Is this approach maybe too childish, too naive?" But at the same time I was thinking, "Wait a minute. What if someone can really operate like that?" Because if you're honest and you're not judging all the time, everything is going to be better, right? What if I really tried to embrace that? So in Libby's case she's so honest, but she's alone in that honesty.

Q: Why do you think Adam is so willing to take Libby (and Miranda) back despite Libby having left him for Miranda?

A: I think it's as simple as Adam knowing that Libby loves him. She knows he knows that, and he loves her back. Also at that point he's taken the test and knows that Libby is an ally. To me that proves that Libby's not selfish at all, you know? On the contrary, I think she's brave enough to see what happens next. She'll go with it. So, there's no point in having any second thoughts about taking Libby and Miranda back. They're on the same page now.

Read a Q&A with David Costabile, who played David, and with Sonya Cassidy, who played Alison, on last week's episode.

Get more exclusive Soulmates content and videos directly to your inbox when you sign up for the Soulmates email list.