In Shakespeare’s Romeo and Juliet, the relationship between the two principal actors fulfills the idea of “courtly love” in several ways.
First of all, courtly love was usually a secret between the two lovers and a few close confidants. Usually the two were forbidden to be together for some reason (sometimes because they were already married to others!). In Romeo and Juliet we know that the relationship must be hidden because of the feud between the Montagues and Capulets. Romeo and Juliet have to sneak around to communicate and see each other.
In courtly love it is also customary for the male to be very lavish and “over-the-top” in his praise of the female. In the passage from Act II below, Romeo has seen Juliet step out onto her balcony. Notice how he describes the beauty of her eyes and cheek:
The brightness of her cheek would shame those stars,
As daylight doth a lamp; her eyes in heaven
Would through the airy region stream so bright
That birds would sing and think it were not night.
The play departs from one tenet of courtly love when they actually do spend a night together. Often courtly lovers were never able to actually have a physical relationship.
Courtly love includes praise of the beloved woman, who is superior and can be approached only with restraint and veneration. The lady is the recipient of poems, songs, bouquets, and elaborate gestures. For all these elaborate efforts, the lady need only return a small hint of approval.
In Shakespeare's Romeo and Juliet, courtly love is displayed. When Romeo first sees Juliet, he speaks in the courtly praise of emotions:
Oh, she doth teach the torches to burn bright!
It seems she hangs upon the cheek of night
Like a rich jewel in an Ethiope’s ear,
Beauty too rich for use, for earth too dear. (1.5.42-45)
Then, when Romeo approaches Juliet at the banquet being held for Juliet his love is expressed poetically and he praises Juliet in the courtly love tradition:
If I profane with my unworthiest hand
This holy shrine, the gentle time is this,
My lips, two blushing pilgrims, ready stand...(1.5.93-95)
Juliet then responds with the "slight approval" of courtly love to Romeo's offer, tempering his passion as she suggests that they just touch the palms of each other's hand.
See how she leans her cheek upon her hand!
Oh, that I were a glove upon that hand
That I might touch that cheek! (2.2.23-25)