Callie (Maia Mitchell) and Brandon (David Lambert) will hit a rough patch in their relationship in the upcoming episode of the hit series "The Fosters."

In "Mixed Messages," CarterMatt reports that Brandon is suspecting Callie of divulging their secret to a friend. During the midseason finale, they gave in to temptation and slept together. Brandon immediately regretted what transpired, however, when the court decided that the family could finally adopt Callie. How can he be a sibling to a person he already slept with? What is more, Brandon is scared that their parents will learn of the truth.

The upcoming episode will show him asking Callie if she shared with anyone that they had sex. In the Foster home, they act like brother and sister, with Stef (Teri Polo) and Lena (Sherri Saum) never guessing that there is more to them than that. If they learn they are romantically involved, Callie could be sent away. All the hard work they put up with the adoption process will be wasted, as the couple will surely not allow any hanky-panky in their house.

In an interview with TV Line, Mitchell talked about her character's mindset for season 3B. She said that Callie would be working hard to set aside her feelings for Brandon and become a true member of the Fosters. Circumstances, however, will make her attempt to move on very hard, as the promo teaser suggests. The actress said that it was going to be "push and pull" for Callie and Brandon, as they try to rein over their feelings for each other.

"It's hard for both characters... It's that process of letting go. Everyone handles it differently. But they both have the same goal in mind, which is to allow her to be a member of the family. They're both really working at finding their own happiness aside from each other. That's a really healthy thing for young people to do," Mitchell shared.

"The Fosters" season 3 airs Mondays at 8 p.m. EST on Freeform (formerly ABC Family).