Nolan & Chen

I am halfway into S5 so maybe I am missing something BUT... I hate the fact that Nolan and Chen were together at the beginning of the TV and it's never brought back. They broke up because it could interfere in their progress but they still dated other people in other similar Departments + Chen is dating Tim.

I know it was a weird couple (age and all) but idk, I would love any comment on their dating past. Past the first half of S1, it's like never happened.

What do you think?