Fruit candies are the guilty pleasure, not babysitting strangers' kids on airplanes. You're probably right, ALittleSurreal; in hindsight, I should have managed the situation differently, and these days maybe would. But I am not a very outspoken person in general, and this was several years ago, when I didn't have as much flying experience as I do now, and to be honest, I wasn't paying too much attention to what was happening until it was too late--in the middle of late boarding of an overbooked flight--to try to get the flight attendant's attention and arrange some seat swaps. It wasn't until much later, when I went back to the bathroom once and saw the mother snoring peacefully away, that I realized how I'd been taken advantage of and felt annoyed.
Anyway, not unrelated to coping with annoyances and definitely related to the topic of this thread, guilty pleasures while flying, I have since learned that fruity candies go great with gin and tonic.