How would I fix my ContextActionService script?

Here's the problem: When using game:GetService('ContextActionService') to make mobile controls for my game, I use a debounce called Allowed. It controls whether the buttons should be active or not. I tried to use this code to make it happen:

local CAS = game:GetService('ContextActionService')
while true do
if Allowed then
CAS:BindAction('function', predefinedfunction, true, Enum.KeyCode.Z)
end
end

The code seemed fine to me, until I tested it. Immediately after Allowed was set to true, It spammed the function it was binded to. I can't seem to figure out why.

Please help.