Jude is in her house where she is able to lure him into her bedroom and bed and then attempts to have sex with him, but he panics and runs out of the house.
At age 10, we see them in 'Garden of Eden' type setting, where they share (presumably) their first kiss. Both are completely naked. Full frontal nudity including close-ups of their genitals.
Two 12-year-olds dance together on the beach, in their underwear. They decide to "French kiss" each other and then the girl invites the boy to touch her chest, which he does, and she comments that she thinks they will get bigger. At this point they embrace, and she says "It's hard", implying he has an erection.