With the Stephanides family vacation canceled (either there was a war in Greece or Chevy Chase had a scheduling conflict), Calliope is free to spend some time at the Object's vacation house in the woods with her parents, Jerome, and Jerome's friend Rex.
Calliope is jealous that the Object gives Rex attention.
The teenagers head out to a tiny cabin in the woods (not this one), where everyone couples off—the Object with Rex and Calliope with Jerome—and has sex at the same time.
While making out with Jerome, Calliope has an out-of-body experience in which she transfers her consciousness into Rex's body and feels what it's like to sex up the Object.
Pain snaps Calliope back into her own body—Jerome has penetrated her and it hurts.
She's afraid that he's going to know that she's not like other girls, but "He hadn't noticed a thing" (3.9.173).