Notwithstanding Friar Laurence's role as spiritual adviser (Romeo's religious father), the priest/monk does play a role as a surrogate father to both Romeo and Juliet. There are two incidents in which Friar Laurence plays a strong paternal role, teaching Romeo and reprimanding him.
1. After Romeo and Juliet's passionate collision in Act I, Scene 5, in which Romeo is struck by Cupid's bow and woos Juliet under the moonlight in Act II, Scene 2, Romeo rushes in the early morning to Friar Laurence in Act II, Scene 3, to ask the priest to marry Juliet and him. Immediately, Friar Laurence realizes that Romeo must have been up all night; otherwise, Romeo is "uproused with some distemperature." He is also surprised that Romeo is no longer in love with Rosaline, and he cautions him to show strength and not change his mind so quickly because women may succumb to other influences when their men are unreliable themselves. He gives this fatherly advice:
Lo, here upon thy cheek the stain doth sitOf an old tear that is not washed off yet.If e'er thou wast thyself and these woes thine,Thou and these woes were all for Rosaline.And art thou changed? Pronounce this sentence then:Women may fall when there’s no strength in men. (1.3.75-81)
However, on second thought, the priest feels the marriage of Romeo and Juliet may be just be solution to end the "households' rancour." Nevertheless, with sound fatherly advice, he tells Romeo to not be so impetuous and hasty with his decisions. His fatherly warning is given to Romeo who says, "O, let us hence; I stand on sudden haste," as the priest cautions, "Wisely and slow; they stumble that run fast" (1.3.93-94).
2. In another incident, after Romeo has slain Tybalt, he runs to Friar Laurence and impetuously considers suicide. Friar Laurence scolds Romeo, telling him that it is unmanly—"ill-beseeming"—to act as he is. Romeo is hysterical, worried about having murdered Tybalt, and worried that Juliet no longer loves him. The priest chastises him for his conduct, and tells him that he should consider himself fortunate to be banished, rather than put to death. Further, Friar Laurence suggests that Romeo be philosophical about what has happened, but Romeo is too distraught. At this point, much like a father would do, he rouses Romeo with some positive realities in his rather long monologue. First, the priest tells him to act like a man; then, he gives him some good reasons to be grateful:
....What rouse thee, man! thy Juliet is alive,
For whose dear sake thou wast but lately dead
But thou slew'st Tybalt; there are thou happy:
The law that threaten'd death becomes thy friend
And turns it to exile; there art thou happy;
A pack of blessings lights upon thy back:
Happiness courts thee in her best array....(3.3.135-142)
Finally, Friar Laurence instructs Romeo to go to Juliet, and then leave early or disguise himself and run to Mantua. While he stays there, the priest promises to send a man with news from Verona.