No, I blame the girl for not being mature enough to understand
that it's not her boyfriend's fault that he can't always be with
her due to NS.
I've seen it happen too many times to my friends. Their girlfriends
would get angry over their bfs not calling every night (they never
heard of night training, I guess), their bfs not going out with
them on weekends (they've never heard of extras and guard duties, I
suppose).... the list goes on.
Besides, for every failed relationship, I also see relationships
which grew stronger because of NS. As they say, absence makes the
heart grow fonder, and this did apply to the relationships of some
of my other friends.
Bottom line... it's not a matter of whether or not NS is the reason
for the breaking-up of a relationship. Rather, it's a matter of how
you react to the difficulty of having NS in the equation.
If the girl thinks that she can't live with having the guy stuck in
NS, then seriously, the guy deserves better.
