In the days that follow, Hermione and Ron are definitely not getting along.
Hermione has to figure out someone new to take to Slughorn's Christmas party, as she had been planning to bring Ron until, well, you know.
Harry had thought he and Hermione would go together as friends, but by the time he runs this idea by Hermione, she's already asked someone else. Who? It's a surprise.
That leaves Harry dateless, and Hermione tells him he can't just take any old girl. Case in point: there's Romilda Vane, who apparently has been trying to trick Harry into taking a love potion.
Yes, that kind of sneakiness sounds right up Harry's alley. Not. He says he'll take someone cool.