How does the author use foreshadowing in Dog Sees God: Confessions of a Teenage Blockhead?

In "The Hangover," Matt focuses intently on CB kissing Beethoven at the party last night while Marcy wants to discuss their threesome with Tricia. Marcy is obviously interested in Matt at this point, betraying Tricia who liked Matt before the party, but Matt's singleminded focus on CB and Beethoven foreshadows the discovery that Matt is in love with CB.