To 'complicate' matters further, his train is running late. [=his train is running late, which makes the situation even more complicated or difficult]
This 'complicates' things. [=this makes the situation more difficult]
Changing jobs now would 'complicate' her life.
(..) Where was that? We never got on. You can't get off if you don't get hang Peter. I don't think i's that simple. Of course you don't, because you complicate things. You don't understand. I'm not an empty seat anymore. I'm different. Punch me, I bleed. I have to go. (..)2004 Spider-Man 2