how to resize clip but not mask in after effects

I would like to have a clip change size, but to keep the mask that’s hiding part of it the same size. but, no matter what i’ve tried the mask always seems to be bound to the size of clip, which in many cases is exactly what you want, but it’s not what i want right now.

i tried shift drag and all that, locking or unlocking doesn’t seem to change anything. idk, i feel like this should be something simple, like a checkbox, or modifier key, or something like that, but i can’t find the solution. please help. i can’t find the answer anywhere.

via Video Editing Forums: Digital Director – Adobe Premiere, Premiere Elements, and After Effects http://www.videoforums.co.uk/adobe-premiere-premiere-elements-after-effects/43621-how-resize-clip-but-not-mask-after-effects.html