I'm able to register devices on TV Go specifically for Virgin Media. It doesn't mention Sky Sports. But you can login to Sky with a Virgin Media login.
There is a distinction between registered devices and devices that are logged in.
I have 5 registered devices. Its possible to login and watch sky sports via a browser on a PC too (doesn't count as a device, or does it).
The popup message when I tried to watch Sky Sports was that I was already logged in elsewhere and only 1 device at a time could be used. This is all very well if the message said where/which devices were logged in.
This is what I'm trying to determine. Where am I "logged in", whether it be devices or browsers.
I explicitly opened and logged out of all devices but it still wouldn't allow me to watch. From there on its guessing game on which of about 6+ options for browsers to fiddle about with.