Here are the things you'll instantly regret doing on a plane

From laptop-killing lattes to barefoot bathroom blunders, here are the things you'll wish you never did when you fly. How many of them have you done?

What do you regret doing on a plane? Chances are, it involves a drink.

As in, drinking and working on a computer. That's what Peter Lewis did on a recent flight from Minneapolis to New York — with disastrous results.

There was a cup of coffee next to his laptop, "and sudden turbulence that shook the plane violently," says Lewis, a consultant based in Paol…