I was kinda hoping it would be Jirou she saw with another girl to give her a metaphorical kick in the ass to sort out her own feelings and commit to pursuing one guy. Up until now, I feel like she's been hedging her bets and leading Jirou on so that she has Plan B guy to fallback on in case it doesn't work out with her with first pick. Thankfully, she seems to have realized this, feels guilty about it, and is sincere in wanting Jirou to be happy, in addition to herself. Hopefully that doesn't all go up in smoke now that it's confirmed (to the surprise of no one reading this) that lover boy is in fact a player; unless the author is deliberately misleading the characters and the audience for drama. It also wouldn't hurt for her to stop being such an obnoxious tsundere and sending mixed signals to Jirou if she wants him to reciprocate her advances; especially if Shiori doesn't pull her head out of her ass and he stays single.