Mount network share (AFP/SMB) for multiple users (fast user switching)
Setup your NAS to export a NFS-share. Refer to the Synology knowledgebase how to do this or use the following how-to to set it up, fine tune and secure your set-up.

You may do it manually in the command line also:
Let's assume your media folder is /Shares/Media. Create or edit a file named exports in /etc. The example below restricts the access to computers with an IP address in the range 192.168.0.1 - 192.168.0.254. You may have to restart your NAS or at least nfsd (nfs-daemon).

Linux/NAS file /etc/exports:

/Shares/Media 192.168.0.0/255.255.255.0(rw)


if you use a Mac Server use this line:

/Shares/Media -network 192.168.0.0 -mask 255.255.255.0

Edit /etc/auto_master on your Mac and add the line:  

/-                                  auto_media


file /etc/auto_master:

#
# Automounter master map
#
+auto_master                        # Use directory service
/-                                  auto_media
/net                                -hosts      -nobrowse,hidefromfinder,nosuid
/home                               auto_home   -nobrowse,hidefromfinder
/Network/Servers                    -fstab
/-                                  -static

and create a new file auto_media in /etc on your Mac

file /etc/auto_media:

/Media         IP-NAS:/Shares/Media

Please don't forget: all files mentioned above need a trailing empty line
enter sudo automount -vc in Terminal on your Mac with the output:

$ sudo automount -vc
automount: /Media updated  
automount: /net updated  
automount: /home updated  
automount: no unmounts  



/Media will now always be visible in the root folder of your Mac and accessible for both of you as long as the NAS is up &amp; running. No Apple Script to mount it nor a Connect to Server needed. 

(Set up and tested on a Server 10.7 (no Synology NAS, because i don't own one, but it shouldn't make a difference) and Client 10.9)