PLEASE go back to sleep. Please please please. We were frustrated that you were up until 12:30 a.m. Mommy was up for a few hours after that, thanks to missing her window to fall asleep easily because you were still up. Eighteen-month olds need more than four and a half hours of sleep. Trust me, we'll both be cranky if you don't fall back to sleep.
Thank you for your understanding,
P.S. Pretty please???