Boys Will Be Boys
Bright laughter rose from the elf standing on the ground far below them. “You got up there, you can get down. One foot at a time, it's easy.”
Elladan looked at his brother perched high in the neighboring treetop. “'Easy', he says,” he growled in Quenya. “If we ever manage to get back to solid ground, I'll give that Sinda 'easy'.”
“Careful, this is a diplomatic mission.” Elrohir replied. “I don't think Father or King Thranduil would approve of our damaging the Prince.” He paused as more laughter sounded, then nodded at his brother. “All right. Minimal blood and bruises.”
A/N - What was harebrained? Was it the climb to the top of the trees? Perhaps it was the Twins' intention to pummel the young Prince. You decide.