Blaine at the end of that episode, man.
You can tell, even in the quiver of his voice when he confirms that the other roles are just fine, that he wants to be Tony really bad. Blaine’s used to being the lead guy, the star as you will, and he’s good, they loved him.
But Blaine can’t do that to Kurt, the idea of crushing his Boyfriend’s dreams like that pains him so much, just look at him. Kurt longs to be a star, and he flaunts that, but how do we know that Blaine doesn’t want it just as badly, but instead chooses to keep it in? Blaine knew it’d be okay if he just didn’t audtion for Tony, but he didn’t expect this and now he doesn’t know what to do, the role is layed out in front of him to take, and he really wants to.
Blaine is a fucking amazing boyfriend.
That’s why, whatever he does choose to do, he still will be, because as much as I love Kurt, if roles were reversed there, I’m pretty sure he would have snapped up the chance to audition for Tony. So Blainer even pondering so much over it is something.