Disclaimer: I don't own the characters.
Setting: after 'Walk Like A Man'. It was begging to be written.
"The first rule of Girls' Club is - you don't talk about Girls' Club." - Abby, Walk Like A Man
Of course she doesn't tell Carter what they're really up to on their nights out. They don't discuss it with the rest of the staff, just make casual remarks about having fun and cute guys. They don't talk about the rest of it. They were all there for the reaction to Weaver, after all. They know what the response would be.
Besides, it wasn't as if they intended this to happen. Well, Abby didn't. Maybe Susan had, when she suggested a "girl's night out". Susan, who knows how to touch her in ways that Carter can't even conceive of. Maybe this was what she planned all along. Abby doesn't care.
She doesn't care because she's got the memory of last Saturday night to keep her going, Susan and her and Jing-Mei, dancing wildly in the clubs and then back at Susan's place, dancing until the tension gets too much and someone kisses someone else, and they make their way to the bed, and take off their clothes, and fuck. Only she's reluctant to call it fucking anymore, because it's started being more than sex, being more a 'making love' sort of thing, and it doesn't just end once they come. It lingers in work. She feels Susan's eyes on her when she's supposed to be examining a patient, and Jing-Mei's fingers touch hers when she hands her a chart.
So she doesn't tell Carter what they're really up to, because she knows he wouldn't get it, never will.