Lena wants Mariana’s quinceañera to be perfect, but Mariana uncovers a secret that may ruin her day. Meanwhile, Lena’s mom visits; and Stef reminds Brandon of the dating rules when she observes his and Talya’s friction over Callie.
Mike invites Brandon to move in with him, which leads to an argument between Stef and Brandon. Meanwhile, Mariana objects to Jesus dating Lexi; and Callie’s journal assignment sparks memories of a dark secret from her past.
Lena and Mike disagree about whether to punish Brandon. Elsewhere, Jesus tries to cover for Mariana and puts his health at risk in the process, while Callie gets blamed for Mariana’s transgression; and Jesus and Lexi embark on a secret relationship.