I feel like they would both do their best to stay out of each other's way (Lorenzo pretty much locks himself in his room), but their morning schedule would conflict, since they wake up at about the same time and basically have the same routine. Despite not communicating much, they'd have a pretty solid setup of how to split chores around the apartment. The house would be immaculate, they'd both take turns cooking, and the rent would be paid on time, no exceptions. Lorenzo would feel a little awkward if he walked in on Maren trying to reach something too high up for her, since he gets the feeling she doesn't like asking for that kind of thing. The most conversation they would have is about each other's respective military.
Oops, got ninja'd! Just a sec!
Lorenzo doesn't care much for socializing, so he'd be as good as invisible unless a matter of extreme importance comes up. Other than that, they only see each other only in passing. Sometimes the house will be cleaner, and sometimes food will appear in the fridge with a sticky note attached labeled "Help yourself". Any attempts at conversation would e cut short due to mutual distrust, and overall, they have a distant relationship.