When is Romeo ungrateful other than in Act 3, scene 3?

In Act 1, scene 1, after the fight between the Montagues and Capulets, Benvolio speaks to Lord Montague about Romeo.  Montague wants Benvolio to try to learn what is bothering Romeo because he and Lady Capulet are very concerned about his well being and emotional health.  Lately, Romeo has been quite depressed.  Benvolio asks if Romeo's father has any idea what the reason for Romeo's sadness is, and Montague responds, "I neither know it nor can learn of him" and that Montague "[him]self and many other friends" have tried to learn its cause (1.1.147, 1.1.149).  Thus, it sounds as though Romeo's father has tried many different time and several methods to help his son, to find out what's wrong.  He says, "Could we but learn from whence his sorrows grow, / We would as willingly give cure as know" (1.1.157-158).  Montague and his wife really want to find out what is bothering their son because they very much desire to find the way to fix the problem or cure whatever it is that ails him.  However, Romeo has obviously ungratefully rebuffed his parents attempts to be there for him, ignoring his mother and father's concerns and refusing their assistance.  This behavior shows his lack of gratitude for their efforts.