Warning: Spoiler alert! Do not proceed if you have not watched Friday's episode of Crazy Ex-Girlfriend...



There’s a new Greg in town, and Rebecca may never be the same.



Well, technically, it’s a new person playing Greg (hi, Skylar Astin!) in the exact same town (we love you, West Covina!), but if you caught Greg 2.0’s very meta entrance two episodes back, you’ll know that much like with Roseanne’s Becky One/Two scenario, everyone at Crazy Ex-Girlfriend is in on the joke. In fact, Astin taking over the role from Santino Fontana isn’t just to mine laughs, but rather an intelligent way to show how much the newly sober Greg has changed and grown since the last time we saw him in Southern California. (Astin’s introductory episode was even cheekily called “I'm Not The Person I Used to Be.”)



Friday’s episode, titled “I Can Work With You,” proved just how much he’s changed, considering how quickly he didn’t run away from the crying infant that Rebecca (Rachel Bloom) was babysitting and the fact that they slept together once again, which isn’t all that surprising a plot point now that Greg is back, but considering she slept with his father, it’s a small miracle that even with constant 12-step meetings, he’s managed to get over that.



Earlier this week, ET chatted with Astin about becoming Greg 2.0. The show hasn't finished filming its fourth season yet, so even the 31-year-old actor doesn’t know what happens to Greg and Rebecca in the series finale, we did discover more about Greg’s big return, how Fontana felt about his buddy stepping into his shoes, and if there’s any hope for Rebecca and Greg really being each other’s OTPs. Plus, there’s even a Bruce Springsteen spoiler alert…



ET: Were you a fan of Crazy Ex-Girlfriend before you got the part of Greg?



Skylar Astin: I was always a fan of the show. I have a bunch of friends who have been on it, and they always raved about what a fun experience it is, and I've never heard such a unanimous point of view like that. Everyone's just like, “Oh, it's a blast!” The reputation preceded them so much that I was like, it can't be that fun, and it actually is. The neurotic mess in me was like, “I'm going to be the only one that gets there and for some reason it's not fun and it's all going to be my fault because everyone else had such a great time.”



Being part of a musical ensemble isn’t new for you, but here you’re joining a cast that’s already been together for three seasons prior. How did you bond with everyone?



They honestly couldn't have been more welcoming. Every member of the cast was genuinely excited about this whole idea [of a new Greg], and I think everyone was also just curious how it was going to all play out when we started doing the scenes, and it just really kind of was seamless. That's kind of weird, because you would think there would be some hiccups or rethinking, but the writers really blazed a trail for me and all I had to do was follow their lead because they handled it in such a smart, clever way, as promised. Thankfully it all worked out, and I'm having a great time. I don't even really think about another actor playing the role anymore because I now think about that as a part of the character's history. There's a respect and a definite awareness of where he's come from, but I just don't associate a face with it anymore.



Have you heard from Santino?



Yeah, Santino's a good friend -- we did some theater together in New York. When he found out, he was truly excited and texted me, “Looks like we're brothers from the same mother,” and we just have such a laugh about it. He's obviously so busy doing Tootsie, and he wished me the best and wanted to catch up afterwards. With these kinds of things, any actor is going to be happy for a friend of theirs who's also an actor.



How would you describe this new, sober Greg to someone?



Greg still has his wits about him. He's still got some dryness and maybe it's sardonic at times, but I think he's evolved into being a more forgiving person. When you're in the program, as he is, you have to be grateful for people sharing difficult things with you, like Rebecca did in episode eight, and you know that you have to keep a lid on your anger, if that's been a previous problem for you, so I kind of filter every scene through that. Not that I am taking every scene incredibly seriously and stripping the comedy away, but more if there's a moment or two in a scene where there's a bit of a nuance, like new Greg would actually probably not be as hard on this person or be a little bit more forgiving in this moment. That's been really fun. Aline [Brosh McKenna, Crazy Ex’s showrunner] and I communicated a lot about that in the beginning, and I think that seed planted very well in my head when I play Greg.



Rachel and Aline have a very clear picture of what they want but also seem to let you guys play.



They really do! I am always encouraged to go with an instinct if I want to add a line here or there, especially if it's a funny improv, and I've seen even in the couple of episodes that have aired, they've put them right in there. They really appreciate me bringing a bit of my personality or humor into the character. They create a very fun, safe workplace. It's a bit of a playground, and everyone's extremely hard-working but having fun. It's very rare. It's kind of annoying that I only came on for half of a season and all these other regulars had four seasons of this, because I'm like, can we do a season five? I'm having a lot of fun here.

Robert Voets/The CW

This didn’t go quite as I had expected, but rather than run when he sees Rebecca with a baby in episode 10, Greg hangs in there and actually ends up babysitting. Is this a bit of foreshadowing or simply a level of ease the new Greg has in these insane situations that Rebecca is always in?



I don't know anything about foreshadowing -- I truly don't know the ending of this series, particularly how it pertains to my character -- but that was another moment to show Greg's progress and something kind of surprising about Greg. If he just did what everyone would think he would do in that situation, then there wouldn't be any growth, so a lot of Rebecca and Greg's story moving forward is like, ordinarily, they would probably act a certain way -- now how would they react? It's just like with any complex relationship with history, it's a good thing that they brought Greg back so they can kind of show where Greg and Rebecca are at now as opposed to years ago.



Fans hoped Greg would come back, and now here he is with Rebecca, and they end up hooking up again. Are we setting them up to truly try being in a relationship again?



It's more like let's see what happens. There's some unfinished business with Greg and Josh (Vincent Rodriguez III), because they really haven't spoken since he's been back. How will that play into everything? Nathaniel (Scott Michael Foster) and Greg were getting along swimmingly in episode nine, but what does this mean now that they're vying for the same girl? Just like the show does with everything else, they don't do anything in the typical fashion -- they infuse it with originality and nuance and quirkiness, so it's not just going to be the three of us angry at each other the whole time and which one of us is going to “win Rebecca.” That's not the case because that's never been what the show's about. It's actually nice that I don't know the endgame, so I don't have to play towards any direction. I just get to be Greg in any scenario when I read the scene.



I'm kind of hoping for a Nathaniel-Greg musical fight scene.



My lips are sealed! It'll be an offshoot, kind of, of your dream…



Do you think Greg is Rebecca's OTP [one true person, a term used in a previous episode)?



It's a big possibility that they could be each other's OTP, but it’s going to depend on if they can use their history to their benefit and not let it take them down. That's kind of the case with any relationship that's had a dark past or some upset or heartbreak. Now that they're progressing and Rebecca handling her mental health issues and Greg is handling his alcoholism and anger issues, will that actually lead them towards each other and will it strengthen their bond? It’s possible. I think it's one of the deeper relationships Rebecca has had as far as a romantic love interest, so I would be on board!



So far, we've seen Greg perform one song with Rebecca and then its reprise in Friday's episode. How different is preparing for songs in Crazy Ex from something like Pitch Perfect?



These are all original, so you have to learn completely new songs, but they are also easy to learn because they're smart and always get stuck in my head. Whatever song I'm doing, the whole crew can't stop singing it for the whole week after we film it, and that's because, yes, you shoot it 100 times, but also the songs are catchy, they're fun, they're memorable, so it makes it pretty easy. I actually get to do a Bruce Springsteen-style song in an upcoming episode, and I had so much fun doing that. Me and The Boss share a birthday, so I felt like it was bashert -- or meant to be, if you don't speak Yiddish.



What does your wife, Anna Camp, think about you taking on this role?



She loves it. She was fully supportive of the whole concept and idea. I asked what she thought of me taking the role in the first place, and she's always super positive and upbeat, especially when it comes to work and getting to play fun roles and doing something ambitious, so she totally confirmed my feelings about it in the first place.



Crazy Ex-Girlfriend airs on Fridays at 9 p.m. ET/PT on The CW.



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