“Holy Saint Francis, what a change is here! Is Rosaline, that thou didst love so dear, So soon forsaken?
Act 2, Scene 4, Line 207
“I anger her sometimes and tell her Paris is the proper man, but I’ll warrant you, when I say so…”
Juliet is deceiving herself making herself think she loves Romeo when she just met him. She is convincing herself that she loves him, then she doesn’t, then she does again.
This is Friar’s reaction to Romeo telling him he is no longer with Rosaline. Friar, a man who is supposed to be a wise advisor, is saying how his she so soon gone after how much Romeo loved her. This shows deception because Romeo is deceiving himself that he loves Juliet this much to completely forget about a girl he had loved so much.
The Nurse is deceiving Romeo by making him think she has a power over Juliet, and at any time she can make Juliet not love Romeo. This, being not true, deceives Romeo making him think he has to suck up to the Nurse.