Where are you even getting that confidence from, Mai? And see! Look here! Here! You have the capacity to be a super splendid friend! Your friendship with Sena is beautiful! Beautiful! If you had just given Renako the fair treatment ahe proposed in the first place instead of pushing for the lover thing constantly you could have been her lover already. But no you and your selfishness lead to disasters! Disasters. You Disaster Lesbian, Oozuka Mai! Baka! Idiot! Excellent Friend! Impulse Aho!
If you are so good at the aspect Renako wanted from your relationship in the first place and a so called genius why didn't you just have a friendship where people wouldn't be surprised if it turned out romantic and upgrade it when Renako was used to the romantic aspects. Instead! Instead! You fudged it! How do you still have confidence when you fudged it so bad? And.... Mai-chan. Are you telling me you can't see how down bad Renako is for Sena? Really? You can't tell their love is romantic and mutual and not one-sided? Mou! You have too much confidence! You're blinded by it!
Meanwhile Our Girl Sena. She's already Best Girl. But she's getting Even Better now. She's, cute , grounded, considerate, loves her friends, a gamer, loves her family, good at cooking, a little stubborn, kind, has natural chemistry with Renako, and their relationship progressed naturally to this point in a way both parties were okay with. Most of all the attraction was mutual from the start.
I don't know how Mai thinks this is going to end or how she came to that conclusion(actually I do, that Confidence Baka) but like the conclusion of Sena's confession to Renako is incredibly obvious.