Spencer Grammer, Scott Michael Foster, Lea Thompson, Jim Abele

When Greek returns, Cappie (Scott Michael Foster) and Casey (Spencer Grammer) will be heading into an uphill battle to save their relationship. Enter Cappie's parents, who come to town to help the new pair find some clarity. TVGuide.com sat down with Lea Thompson — who plays Cappie's mom, April — on the set of Greek to find out how the parental units will save the couple during the '80s themed episode. Speaking of the 1980s, Marty McFly's mom — now 48 — also discusses how Back to the Future shaped the, you guessed it, future.

Watch full episodes of Greek

TVGuide.com: How did you come to guest-star on Greek?
Lea Thompson:
They just asked me. It just seemed perfect. They offered it to me and I hadn't seen it too much because I'm not their target audience, but I had a room full of teenage girls, my daughter and my niece, and said "They want me to play Cappie's mom," and they flipped. "Cappie's mom! You have to do it!" They all loved it, so I caught up with episodes on ABCFamily.com and I fell in love with the show, so I'm really happy to be here.

TVGuide.com: Why are Cappie's parents coming to town?
Thompson:
They have very important news to tell him. It's just shocking what they're going to tell Cappie. They take Casey and Cappie camping. We're earthy people, so we take them camping. More New-Agey than hippies. We're open and free-spirited, not corporate America. I think we're here to make some clarity for Casey about their relationship and what should happen with them. She will see that you can't really change someone. When you love someone, you can't change them. You have to let them be who they are.

Greek's Spencer Grammer: The Casey-Cappie coupling won't be a "boring love story"

TVGuide.com: Do you get a lot of people who still recognize you from Caroline in the City or Back to the Future?
Thompson:
Yeah, it's kind of sweet and surprising. With Back to the Future, young people weren't even born when it was made and they know the movie. I'm really touched by how much life it has. Now they're remaking Red Dawn, it's so strange. This episode of Greek is maybe one of the reasons they were thinking about me. It has a whole bunch of references to '80s movies because they're having an '80s dance. So they probably started writing something about Some Kind of Wonderful and thought, "Why don't we just get her for that?" They mention Pretty in Pink, St. Elmo's Fire and all those movies that people really love. People love Some Kind of Wonderful, young people who were not even alive when it was made, which is lovely. I feel very honored.

TVGuide.com: When you were filming Back to the Future did you think that it would become such a huge part of pop culture and history?
Thompson:
No, I didn't. Bob Zemeckis and Steven Spielberg were there all the time, so I knew it was a big deal, but I didn't realize how much it would endure. It endures because it's got a really powerful story. I think the story actually touches you and you don't realize it because it's funny and interesting. The whole idea of saving your parents from themselves is an awesome idea. It's very sweet and that's why it endures. It was also a perfectly crafted movie. Most of those science fiction movies fall apart. If you watch it again, you think, they never even bothered to thread that. Every single thing in Future pays off, every joke pays off. It's beautifully made.

ABC Family sets date for Greek's midseason premiere

TVGuide.com: Since you've been in the business for so long, now working with these young actors on Greek, do you look at them and see yourself in them?
Thompson:
The lovely thing about being an artist is that it crosses ages and generations. We do the same thing, we're on the same journey. I love hanging out with young artists because they don't think of me as older. We're people who have to get in together and work. I have to say, I was kind of nervous. ... so I was saying to Spencer, "Will you run these lines with me because I'm kind of nervous because I don't know you guys. I feel vulnerable." She said, "Oh, I totally get it, let me help you out." We're just like comrades.

Greek returns to ABC Family on Monday, Jan. 25 at 10/9c.