I’m not sure whether I approve making your dad shit his pants, but you can activate a license on two PCs. The caveat is that normally both have to be yours since this is not meant for sharing a license. Your dad’s PC is OK though.
Just send the request code shown on the second PC to the register mail address and you get a second key.
Hello Ralf, i’m in a same situation here. At Parents’s home for holydays, and i want to make them try few things in VR. I’ll send request code from that PC soon.