>>91507104Well, Zii and Yuki were dating at that point, and broke up way before she met Gary.
She's upset because she's found herself wanting Gary's dick lately, and been trying to keep her mind off of it because she promised to get him laid (and doesn't seem to grok he's into her, too). She's also wanted to fuck Didi since the day they met, and this is the first real chance she's gotten SINCE then.
She's upset because in her attempt to convince Didi that bumping uglies with a friend post-breakup was fine, she talked Didi into fucking Gary. So two people that she really wants to have sex with are very loudly having sex 20 feet away from her.