For a few weeks BTMM hasn’t been working for me, so when I’ve needed to take control of my dad’s mac I’ve needed to take control as a normal VNC client. This involved talking him through finding his mac’s IP address.

Anyway, BTMM now appears to be back with us, so there’s no need to talk-down. In the screenshot, MIA (on the train) is observing/controlling Iggy (in Edinburgh). In turn, Iggy is observing/controlling my dad’s mac (in Worcester).