"Realizing"? She asked him about it and he lied to her.
Yeah, maybe she ... "showed questionable judgement" for believing his lies, but he actively lied. What does that say about his judgement?
While it is kind of odd that one can go out with someone for 6 months, live in the same city as them and never visit their house.... this guy was actively lying.
Its entirely possible, wanted to visit his place all the time, and gave a laundry list of bad excuses until she finally broke up with him for being dishonest as the relationship was becoming increasingly serious in her mind.