I'm at the airport. iPad Air on free wifi; iPhone 5s on LTE network. I look down to see my phone is on wifi. Shouldn't be; I never connect to the wifi here. So I forget the wifi network on my iPhone. My iPad then disconnects from free wifi on its own. So I go back to iPad and join the wifi network, and then my phone again connects to the wifi network. What the hell? I'm pretty sure this isn't a "feature." I can't find a setting to disable this. What the hell, Apple?!