Sharkbite

What happens when you don't remove the sleeve when attaching the sharkbite to cooper? I'm asking because I did it.

Nothing its just easy to install without one in.

Per the Sarkbit website "The SharkBite® fittings have an integral Tube Support Insert that is effective in supporting PEX tubing to ensure the O-ring seals correctly on the outside of the PEX tubing. The Tube Support Insert is not required when using CPVC and copper tubing; however it is not necessary to remove the insert when using these materials."