if rebooting is and option, it will release the mounts. And should be safe because mounting on top of an existing path doesn’t really break anything. the original files still exist, but are just hidden because they are under the new mount. Once the mount is released, everything should be as it was.

Yes.

you most likely have a terminal open that is currently in that path.

umount -f /home/skynet

You can force it.

umount /home/skynet

should release it.

can you see the the mount using mount ?

sudo sshfs -o allow_other,default_permissions shady@192.168.50.16:/home/shady/skynet /home/skynet

You mounted your desktop files on top of the server files.

fusermount -u /home/shady/skynet

this should be

fusermount -u /home/skynet