No, no, and still no. Installing an app on an Android device you've purchased and fully own is not "sideloading". It's just... using your device. Nothing more. Let's not pretend even for a second that "sideloading" is a normal term to describe this.

@zsmb13 I usually sideload bread into my toaster. I buy bread from a different company than that which made my toaster.

(Well, I load the bread in from the top like a normal toaster. ;) )