Alright my little dufflemuffins, Christie here, bringing in Slughorn in probably the worst advised move in history!
Slughorn's a 74 year old bon vivant starting his 50th year of teaching potions, and schmoozing--that's an extracurricular. So someone better throw him parties He's a confirmed bachelor who enjoys hosting parties, favoritism, receiving gifts and joie de vivre.
If he likes you, he loves you, if he doesn't, who are you?
He's a bit of a flirt who wouldn't actually pursue anything, he's past romantic endeavors at this point in his life. I imagine he gets along perfectly fine with other professors, unless they have reason to dislike him, and he's looking to collect tomorrow's best and brightest :D
So, tomorrow's best and brightest, who wants in slug club?