Something that this chapter has been abundantly clear is that all the characters in school need therapy. Sayaka, as noble as her intentions might be, is just someone too afraid to take a chance to get what she wants. Minding your friends' feeling is a good trait, but truth is, Sayaka has just fallen into a routine and thus, is unavoidable she will enter in conflict eventually with Touko and Yuu.
Haha, I think the one who really has the biggest burden is Touko. Sayaka found an outlet for her frustration and I think most people, gay or straight, have had similar situations with friends, romantic or not. She respects her best friend's space and understands how vulnerable Touko is despite the confident front she projects to the rest of the world.