Im actually really tired of Sarah treating Chuck like crap. From the very beginning in season 1, she treated him like an endearing little boy with a crush. Their relationship actually developed and changed in season 2, when they were 'almost' together in Prague and Chuck chose to be a spy over her...feelings like that don't just go away, she must have had some kind of reaction to that, but they didn't really develop that at all. Chuck just moved on to Hannah and Sarah moved on to Shaw. And now that Chuck and Hannah broke up and Sarah and Shaw are still together, she's gone back to treating Chuck like a boy with a crush...leading him on...letting him think that something might happen between them, but pushing him away at the same time. I'm really tired of the whole will they/won't they drama now. It's getting old.
Also, Sarah has a history of falling for the 'real spy' kinda guys - there was Bryce, another guy in season 2 that I don't remember the name of and now Shaw. The reason Chuck want to be a real spy is so that he can compete with all the other guys Sarah has dated. Instead, the more he tries to be like them, the more disappointed she gets in him. It's like no matter what he does he isn't going to be good enough for her. Her character has become monotonous and really annoying to me and the writers definitely need to come up with some more good and original material. Maybe something like a time jump to a year from now after Chuck has gone to Rome and come back a real spy and he sweeps her off her feet like Shaw did and this time she is the one chasing after him instead of the other way around like it's been for the past 3 seasons!!