Yes. If you're both using Messages and your firewalls allow for it, you can share your screens even if you're not the same local network.

Start up Messages and make sure Screen Sharing is enabled:

![Enable screen sharing in Messages][1]

Find your buddy in your contact list in Messages and click on them. Then select `Buddies -> Share My Screen with Buddy...` or `Buddies -> Ask to Share Buddy's Screen...` from the menu bar to initiate a screen share session. You can share control with these sessions.


  [1]: https://i.sstatic.net/dlIAB.png