Take this all with a grain of salt, but I think this may have been his Father in Law.

The Bi-Racial Angel has mentioned on the GrangeTV podcast that he has an acreage, where it's Rob, his immediate family of wife and kids, his dad, his siblings, his Mother in Law and partner, I assume is Father in Law, all living together.

He's also mentioned that his Father in Law wasn't in the best of health, not sure which episode, I've listened to a lot of them the last couple weeks.

Again, take this all with a grain of salt, just speculating here. Maybe Rob will talk about it whenever GrangeTV podcast returns, as he has been pretty open about his personal and family life on the podcast (to an extent).