Built a treehouse with my 6yo this weekend and barely survived

So I decided we'd build a treehouse in the oak tree out back. Got some 2x8s, bolts, a ton of YouTube videos and what I thought was a solid plan. Turns out my kid has zero fear and kept trying to climb on stuff while I was still securing it. Wife was freaking out the whole time. Anyway, we got it done and he absolutely loves it. My back hates me though. Anyone else do projects with their kids? How do you manage the safety anxiety?