Confused by his behavior, I left him alone for a few minutes. I found him later sitting in the baby's room, rocking in the chair.
"Luke, sweetheart, do you want to rock-a-bye with mommy?"
"No," he responded, "I rock-a-bye by myself."
Crushed, I walked downstairs to the sleeping newborn, scooped him up and cuddled him close. At least I have two years and nine months before he can protest.