I'm pretty sure all that doesn't need explaining- Mayaka already pointed out to him previously that he could just say no to Chitanda as well, to which Oreki only replied that it's because he can't say 'no' to her that's why he's doing all this. Even Mayaka realized the meaning of it.
Lol, like
Zeross, I suffered through the horrendous quality of episode 11.5
But it was worth it, because it does show clearly that whether Oreki himself admits it or not, he does value what Chitanda thinks of him.