The closest thing I can find to an answer from the publisher is this bit from Mindi:
"I'm not going to debate copy protection and piracy here. All I will say, is for those of you who think Dom's copy protection is so much more intrusive or strict than other games, you obviously haven't played many games. We actually have a better policy than a lot of games out there (for ex. in general our games are a one player at a time license, not a one computer at a time license), but yes, if you and another person (no matter who it is, spouse or not) want to play simultaneously, then you need to buy two copies."
Post#510927
Is that enough data to answer the question? What you plan on doing sounds like one-computer-at-a-time, not simultaneous play.
-Max