Lemme add a little bit:
X manages to somehow not realize deem was a assassin out for his ass, rather it felt like he was looking past that fact. And whenever deem decided to take him out, he takes HER out.
On a..date?
X was a good shooter, and also has dumb jokes, but deem can see his rude, unsympathetic exterior under his usual mask.
Deem really struggles with her task, and the Mafia boss of the organization she works for has put her Position of a soldier in danger if X isn't gone soon.