The expression of Risa saying that she is glad hearing that Maiko enjoyed the show is making a contrast of what she is saying to what she has on her feelings that is what I am sensing about that. For my own point of view there are a lot actions that she wants to kiss Maiko and she wants Maiko to get jealous and disagree to idea that she will going to kiss Fumi. That is my point of view. My bases are (a) her reaction when Maiko give her point of view about the two of them kissing and about kissing. (b) asking Maiko what they gonna about that (but it also kinda not so supportive evident I think however I will still include because why do you need to ask the other person involve if you yourself may give your own thought first about the idea?), (c) her reaction when Maiko agrees to the idea she gave that she and Fumi will kiss. (d) her facial expression when they started to go outside the fast food chain. (e) the way she is hesitating to do it with Fumi but can't back down. (f) her glance she gave to Maiko before she kiss Fumi...
The last that triggers my feelings about Risa has her hidden feelings to Maiko is the expression she gave at the last page of this chapter.
I could be wrong sooner or later but this is the vibe that I am getting to this chapter.