deleting content off 1 idevice that is still logged into current icloud account

Hi, ok so i have 2 iphones 1 of them is my current one which is the iphone 5s and the other one is my old one which is the 4s. My 4s is still signed into my icloud account and is updated with texts, calls and photos/videos. If i delete the photos and videos off my 4s to make room for backup videos will it delete it off my current 5s? I like recording videos and i want to use my old iphone for storage for my videos i take and download but i dont want it to remove whats on my current device is this possible? i tried using google but sadly nothing