Sings Stacy's Mom: Anyone who has ever had a crush on Toriel ever. Frisk even sang this to her back in the Ruins, much to both their awkwardness. (As an explanation for calling Tori Mom, then flirting with her. :P )
Hates It: "SANS! YOU'VE BEEN SINGING ABOUT LADY ASGORE ALL DAY!!!" Toriel finds it a little odd, but as long as the song isn't sung by Asgore (which he's not suicidal enough to try anyway), she's cool with it.