Mounting directories on demand or until logged

As from object, I want to mount some directories (with binding) at login and possibly unmount them at logout. At the beginning I tought about autofs, but it dynamically creates mount points, that's ok with cli, but not when using filemanagers, it's really annoying to have to write a directory name to make it spawn. Another solution I considered is running a login script, and it works. My problem now is that I don't know how to unmount them. I use LightDM, so .bash_logout is not an option, and also if that login manager can trigger a script when logging out, it runs system wide, and I'd prefer a solution user based. Thanks in advance