'Private Practice's' Paul Adelstein: Cooper 'Really Wants to Believe That This Is His Kid'

The actor tells THR how Erica and Mason's arrival will impact his marriage to Charlotte.
Paul Adelstein on "Private Practice"

On last week's Private Practice, Paul Adelstein's Cooper received a life-changing visitor.

Showing up at Seaside Health and Wellness was Erica (My So-Called Life's A.J. Langer), a woman with whom he had a one-night stand who returns eight years later with her 8-year-old, Mason. Arriving at the end of an episode that saw Cooper and his wife, Charlotte (KaDee Strickland) struggle to get their marriage back on track after suffering another trust setback, Erica's timing couldn't have been worse.

Erica's arrival brings one of Cooper and Charlotte's biggest issues to the forefront: their very different wants and desires when it comes to having children.

The Hollywood Reporter caught up with Adelstein to discuss how Erica and Mason's arrival will impact Cooper and Charlotte and whether the wannabe dad will break down and get a paternity test.

THR: How will Coop respond to Erica's arrival?
He's dubious at first but the kid is super charming and Cooper wants to be convinced that this is actually his son. He emotionally starts to make that leap even though Charlotte and the rest of the gang at the practice are telling him to be cautious. He's excited by the prospect.

THR: How is this going to impact his relationship with Charlotte?
It's challenging. First, you don't know if it's actually his kid. He doesn't remember this woman, really. He may be being very naive. He wants to have a lot of discussions about it actually happening before there's any proof and that presents a challenge to Charlotte and Cooper. He's so dedicated to children, so enamored with the idea of being a father, that he forces this conversation to the fore and it puts a strain on them for sure.

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Will he give into the demands of everyone around him and get a DNA test?
It's addressed [this] week whether he will or whether he won't. He really wants to believe that this is his kid especially after he spends some time with him. He's like, “This has got to be my son, we have all these similarities,” there are some charming things that happen that make him think, “Oh, this has got to be my kid.” Having always wanted to be a father, having a wife that is lukewarm on the idea of parenthood make it, from Cooper's perspective, seem like a perfect fit.

THR: Will Mason and Erica become a regular part of their life? Can Coop have both?
We'll see. People come forward that are trying to protect Cooper that feel like he's not doing a good job of protecting himself. Some people take action to head this off at the pass. It gets complicated very quickly.

THR: Who's going to come in to guard him? Charlotte?
But there are multiple people that are advising him to be more cautious than he's being or advising him to be careful with how this is going to affect Charlotte.

THR: Will Charlotte waver on her feelings about having children?
There's this romantic thing that she says in the next episode, where there's talking hypothetically -- they don't know if Mason is really Cooper's or not but Cooper says, “You don’t even know if you want children, how is this not perfect?” and she says, “Well, I would have thought about it differently if I knew somebody else was going to come along and give you something that I wasn't going to give you or couldn’t give or had ambivalent feelings about." I thought it was a romantic notion. Of course, it makes her question her own ambivalence because she sees how badly Cooper wants this. It’s now actually in front of them.

THR: How much does Cooper trust Erica?
He wants to trust Erica, that's an interesting dynamic in and of itself. Every male in the practice immediately wants him to get a paternity test. The logical side of Cooper's brain says of course, but the emotional side says there's a kid that needs a father and I have this bond with, why do we even have to go there? Cooper is adopted; he knows that parenting isn't really about genetics. He wants to believe that this is his kid and he wants to believe that there is this actual connection but deep down he's nervous about what the answer to that may be.

THR: Could we see Mason and Erica become a part of his life even if the paternity test reveals otherwise?
It would be complicated but it is certainly not beyond Cooper's abilities or what Cooper thinks his abilities are. This is something he wanted for a long time and it’s being presented to him in a real way. He wants to take advantage of it.

THR: Will Erica develop feelings for Cooper?
Adelstein: You never know. Depending on what his relationship with the kid is, would it lead to that? We know how Cooper is with kids. It could get complicated.

THR: How will Mason and Erica's arrival impact the practice?
Indirectly, for the first time it's something coming up in episode we're about to shoot that's interesting, where you see something Cooper hasn't had to deal with -- and people without children haven't had to deal with on the show -- which is, the degree to which he's dedicated to his patients takes away how much time you have for your personal life. Cooper has never had to balance that before. If there's a sick kid in the hospital and he wants to spend three days at the hospital with the kid, he can't. That dedication starts to be a little bit of an issue.

Private Practice airs Thursdays at 10 p.m. on ABC.

Email: Lesley.Goldberg@thr.com; Twitter: @Snoodit