She doesn't seem very grateful, only saying, "that's original" (we can almost feel the sarcasm in that one). Charlie seems to be offended that she's not more excited about it, even though she really has no personal connection to the book.
A few days later, after Rocky Horror, the gang gets together to play truth or dare. Ooh la la.
Patrick dares Charlie to "kiss the prettiest girl in the room" (3.11.23).
Charlie, being Charlie (i.e., nakedly honest at the worst of times), kisses Sam instead of Mary Elizabeth. Oh, Charlie.
Um, yowza. The room is so silent, you could hear a gnat burp.
Needless to say, Mary Elizabeth is upset. She runs out of the room.
Sam isn't too happy either, and she doesn't mince words: "What the f*** is wrong with you?" (3.11.30).
This makes Charlie cry. Not because he embarrassed Mary Elizabeth in front of everyone, but because Sam is mad at him.
Patrick takes Charlie home, where he puts on the Billie Holiday record and starts reading the E.E. Cummings book, both things Mary Elizabeth gave him.
He stares out the window for a long time. "Not feeling anything. Not hearing the record. For hours" (3.11.48).
The letter ends with a troubling statement: "Something is really wrong with me. And I don't know what it is" (3.11.49).