In Romeo and Juliet, the Nurse and Friar Laurence assist Romeo and Juliet in their love relationship. At the feast for Juliet, the Nurse speaks to the Montagues and tells Romeo who Juliet is, adding,
I tell you, he that can lay hold of her
Shall have the chinks. (I,v,111-112)
Later, she reveals to Juliet the identity of Romeo, but hurries her home. After Romeo has received Juliet's promise of love from the Nurse in Act II, he talks with the Nurse, telling her to instruct Juliet to come to the cell of Friar Laurence where they will be wed; the Nurse dissembles for her by saying that Juliet has gone to make her confession. Later, after Romeo weds Juliet, he visits her chamber where they consummate their marriage while the Nurse keeps watch for Lady Capulet.
While the Nurse is probably in indigent relative given a position in the Capulet home, as was customary in the fourteenth century, she certainly should be loyal to this family. So, knowing of the attraction that Juliet has for Romeo, the Nurse is blantantly disloyal to Lord and Lady Capulet by not informing them. Clearly, she oversteps her position when she conspires with Juliet to arrange the wedding at Friar's Laurence's cell.
Similarly, Friar Laurence is complicit with Romeo and Juliet. He performs the marriage ceremony for them without notifying the parents;he sends Romeo to Mantua after he is banished with instructions that he will notify Romeo when it is safe for him to return; he contrives the fatal plan of having Juliet seem dead so that she will not have to marry Paris; this plan is made also so that parents will be overjoyed when she revives. Unfortunately, his plans go awry when a plague strikes Mantua and the friar's servant Balthasar cannot reach Romeo. The friar also abandons Juliet in the tomb as she revives from the potion he has given her.
As a friar, Friar Laurence has taken vows which remove him from the temporal world. For him to be deceitful to the Montagues and Capulets and marry the lovers secretly is clearly wrong. His interference with the lives of these two is surely beyond the boundaries of his vows. And, his failure to reveal to the parents what has transpired is deceitful and wrong. It is also tragically wrong that he runs from Juliet when she regains consciousness in the tomb.