Well, just about everything. For example, in the last scene he abandons Juliet because he is afraid of the watch, thus allowing her to kill herself. He does not reveal that Juliet is already married, even when Paris comes to arrange a wedding, because he is afraid that the families will be mad at him for marrying her to Romeo.
Friar Laurence married off Romeo and Juliet.
Friar Laurence is the friar who marries Romeo and Juliet.
Friar Lawrence married Romeo and Juliet in his cell.
Juliet, Romeo, Tybalt, Nurse, Benvolio Or . . . Juliet, Romeo, Friar Lawrence, Nurse, Capulet Or . . . Juliet, Romeo, Friar Lawrence, Capulet, Tybalt Or . . . Juliet, Romeo, Capulet, Mercutio, Tybalt Or basically Romeo and Juliet and any three of Nurse, Friar, Capulet, Mercutio, or Tybalt.
Romeo, Juliet, and Friar Lawrence are in Friar Lawrence's cell.
She says no, but then the friar is afraid of the watchman that is coming. the friar then leaves without Juliet. When the friar left Juliet finds the poison bottle and is upset that Romeo didn't even leave a drop for her. She then kisses his lips hoping there is poison still lingering on them. She then finds his dagger and stabs herself in her chest. She then dies in Romeo's arms.
Friar Lawrence wants Romeo to do different things depending on what part of the play you are talking about. When they first meet, the friar tells Romeo to go slowly in his relationship with Juliet (as if!).
Friar Lawrence was the priest in Romeo and Juliet
The friar.
Friar Lawence
It was both Romeo's and Juliet's idea to marry eachother.
Romeo asks friar Laurence to marry him and Juliet in secret