A fear of a burglar inside of your shower.
This results in a habitual opening of the shower to "check" for the suspicious person in your bathing area.
"Do you really open the shower when you shit Earl?"
"Yeah... (sigh) I suffer from showerglarphobia. It's a phobia suffered by mainly the smartest, most diverse and awe inspiring people on earth that creates a fear of a burglar or suspicious person, as stated on my police report from when I swear I saw Dick Cheney with a shotgun, inside of you shower when you go to relieve yourself."
"That's bullshit Earl. No such thing exists. Your full of shit."
"No way. its a Facebook group, DUHH!! It exists jackass. The last thing I wanted was a face full of bird shot when I was trying to pinch a loaf in solitude."