Grey's Anatomy
Maggie's relationship with Meredith is going to be strained. Pictured: Actors Kelly McCreary and James Pickins Jr. from the ABC television drama series "Grey's Anatomy" arrive at the 2015 People's Choice Awards in Los Angeles, California January 7, 2015.Reuters

The Season 12 finale of ABC's "Grey's Anatomy" will explore the consequences of Meredith's unexpected hookup with Nathan. Rumours doing the rounds indicate that Maggie will be heartbroken to know about her sister's affair with Nathan, as Maggie has always had a crush on the doctor.

 "I think she's going to be crushed," Kelly McCreary, who plays Maggie, told TVLine. "Genuinely crushed." According to the actress, the next episode will see her expressing a desire to be in love, "so [when she finds out] ultimately that it may not be a chance for her to be in love, I think she's going to be heartbroken."

This will cause a strain in her relationship with Ellen Pompeo's Meredith and "the next phase of Maggie and Meredith's relationship is going to [involve them] having to draw some boundaries around their relationship," the actress previewed.

As for the future of her character's relationship with Nathan, Pompeo said she isn't sure if a romance is in the cards for the duo. For Meredith, her hookup with Nathan might just be something she did on the spur of the moment.

"I'm not sure if the relationship, the sexual relationship, is going to continue or not," Pompeo told TVLine. "I think maybe they want to give the fans a little taste and see how they react first, and then they will decide what to do. Shonda is sort of savant in that way. She just gets these ideas, and she's very, very confident about what direction she wants her characters to go in. So maybe she has a plan for next year."

The synopsis for Season 12 finale, titled "Family Affair," reads: "Meredith and Maggie support Amelia on an important day. Jo reveals that she has been keeping secrets from Alex while Arizona and Callie deal with the impact of their custody arrangement. Meanwhile, Ben leaps into action to help a friend."

"Grey's Anatomy" airs Thursdays on ABC.