Should Buddhist parents engage in idiot compassion? If I am a Buddhist parent and a child is always messy, should I always clean up the mess they make? Are there any sutta teachings to guide parents of messy children?
When children made a "mess" or mistakes, parents could clean their "mess" every time but that would not be wise as they cannot be on their children's side forever. There will come a time when they will pass away. Instead, parents should teach their children to be independent and learn to reflect on their own actions. In Ambalatthika-rahulovada Sutta, Buddha once said to his seven years old son, Rahula: 

"What do you think, Rahula: What is a mirror for?"

"For reflection, sir."

"In the same way, Rahula, bodily actions, verbal actions, &amp; mental actions are to be done with repeated reflection."

References: 
"Ambalatthika-rahulovada Sutta: Instructions to Rahula at Mango Stone" (MN 61), translated from the Pali by Thanissaro Bhikkhu. Access to Insight (BCBS Edition), 30 November 2013, http://www.accesstoinsight.org/tipitaka/mn/mn.061.than.html