Altough this looks promissing i don't think Sugu will confront Asuna, but she will make Asuna very uncomfortable since she can't complain with Kirito why she is uncomfortable or face Suguha, that will be fun.I agree. But I think it will most likely be Suguha. Liz somehow looks lost to the plot so far. And although Liz seems to want Kirito for herself, , she hasn't been very active in the last few updates. And as for Suguha, I think it will be some kind of plot twist - Suguha will persuade Kirito to have sex, of course her will write it down. Then he will go to Asuna, show her and say, "Well, how are you feeling now, sister? You slept with a little pig myself, and now Kirito is no longer just yours."
And I think further along the plot Shinon will tell Suguha that Kirito was not in the brothel. Or does Suguha know that?? Well, the point is that she will say "And Kirito wasn't in the brothel then, sister, you were the only one who cheated both in the game and in real life" "And you ruined your relationship and pushed him away... And I picked him up and he'll be better off with me! Sister..."
I just like the way Suguha calls Asuna sister, even if it's just the credits, I can see the sarcasm in Suguha's words.
I think Asuna will have a surprise when Kirito tell her the content of his halucinations and depending the way he tells her, she can get very worried or think Kirito is fantasizing about the topic.
This is hard to happen but Fujino did create a rare oportunity to punish the Slut for a change.