A source close to the situation explained:
At least according to an alleged insider!
"The relationship kind of brewed out of a friendship and the fact that they had to get into a romance for the show. [The breakup] was inevitable. I think she decided she wanted to experience other things."
Wait… so what, their relationship was purely circumstantial?!
PSHHHH. We shant believe it!
Although it DOES makes sense that Nina would want to experience life on her own terms for a while, without having to think about a romantic partner's needs…
Especially since there's a ten year age gap between Nina and her former boo!
At least, that's how it went down in our heads LOLz.
[Image via WENN.]